In 2015, Perez left Cuba when he was age 19.

Cionel did quickly become one of the top performers in Serie Nacional at a young age. Pitching for Matanzas in Serie Nacional, Cuba’s top league, Perez posted a 2.06 ERA with 76 strikeouts (sixth in the league) and 32 walks in 87 1/3 innings over 17 starts during the 2014-15 season.

Sept 2016: Perez signed with the Astros for $5.1 million. But a problem arose during his medical physical. Perez ended up signed with the Astros for $2 million on December 6, 2016.

Cionel was frustrated and disappointed over the signing process. “I am happy to begin my professional career, but I feel abused by this system,” Perez said in the letter provided by his agency, Octagon, addressed to Major League Baseball and the MLB Players’ Association.

Despite his frustrations with the process, Perez, in a separate statement to Baseball America, thanked the Astros organization.

“I am very happy and I give many thanks to the Astros for giving me the opportunity to sign again, to represent their franchise and most importantly help me achieve my dream,” Perez said through his agency. “I know I have a great opportunity, and I will do my best to maximize that opportunity in hopes of winning the World Series that they deserve.”

During Perez’s physical, the Astros decided that there was an issue with his left elbow and voided the contract. Perez re-signed with the Astros on Dec. 9 for $2 million. Since Perez is signing with the team that previously voided his contract, the Astros will have to place him on the 40-man roster after the 2017 season if they want to protect him from the Rule 5 draft. Had another team signed Perez, that would not have been the case.

Perez signed with the Astros the day after the 2016 Rule 5 draft. If the Astros signed him sooner, he would have been exposed to the Rule 5 draft this year and Houston almost certainly would have lost him.

Perez’s camp argues that, because he is being treated as a previously signed player in this situation, he should be treated as a previously signed player under the international signing system. Per the Collective Bargaining Agreement, players are exempt from the international bonus pools if they are at least 23 and have played five or more seasons in a foreign professional league—a cutoff Perez doesn’t meet—or if they “previously contracted with a major or minor league club.”

Thus, they argue, Perez was previously contracted and should be exempt from the bonus pools and free to sign with any club without restrictions. (Ben Badler - Baseball America - 1/13/2017)

In 2018, the Baseball America Prospect Handbook rated Perez as the 13th-best prospect in the Astros organization. He was at #12 in 2019.

Sept. 2022: Perez decided to play for Team Cuba in the 2023 WBC.

Cionel was such an energetic, excitable child that his parents took him to a psychologist for a year to figure out what was wrong, why he couldn’t sit still, why he continually bounced off walls. The conclusion? It’s how he’s wired. A ball of energy who needed constructive outlets.

Pérez found baseball. And, eventually, pitching. He became one of Cuba’s best by age 18. Ultimately, he escaped to find a better life, spent months in various countries, and was stuck for more than a week in a Haitian prison — initially locked up with an accused murderer and a man bleeding from multiple stab wounds. It’s all part of the treacherous road that led him to Baltimore.

So, when you see Pérez lift his left arm skyward, scream mightily and hug catcher Adley Rutschman as if they hadn’t seen each other in years, understand this: It’s about so much more than strike three.

“It’s a combination of everything I’ve been through,” Pérez said through team interpreter Brandon Quinones. “And about me just being me.”

Pérez can’t remember a time when he didn’t play baseball. Even if it was simply learning the game by throwing and swinging at bottle caps tossed by his father. He originally was a center fielder, slight, exceptionally speedy and with a rocket arm. He didn’t concentrate on pitching until he was 15. An outstanding athlete, he was selected to attend his province’s sports academy, choosing between baseball and soccer.

“I told them I would stick with baseball because I was too short to be a goalkeeper,” said Pérez, who is now listed as 5-foot-11. He also was persuaded to become a full-time pitcher; it would be his fastest way to pro ball.

“I wasn’t great hitting-wise, and I was too skinny,” Pérez said. “They told me I didn’t have a lot of offensive potential. But I had a really good arm, I was a lefty and my ball had movement.”

At 17, two years after he focused solely on pitching, Pérez debuted for the Cocodrilos de Mantanzas of the Cuban National Series, the island’s top professional level. By 18, he was established, posting a 7-2 record and a 2.06 ERA in 17 starts. Scouts from Japan and Korea noticed. They wanted him to sign there. At the time, though, only players who were on a government-approved list could leave for international play, Pérez said. And he was much too young to be allowed to play elsewhere.

It was a fairly common practice in the 2000s and 2010s: Cuban baseball players defecting with help from someone in the United States. The U.S. connection would pay relocation costs and set up the travel itinerary. Once the player signs a big-league deal, the connection receives a percentage of whatever bonus the player secured.

That was the arrangement the Pérez family made. However, they were detained by the Haitian government in the process and thrown in prison. After 4 days living in deplorable conditions with murderers and thieves, they were released inexplicably, never knowing the reason. He finally made it to the Bahamas where he established residency and have the opportunity to showcase his talent for MLB scouts. The Astros requested a private bullpen session with Perez, later that September Perez agreed to a $5.1 million signing bonus. After some physical hurdles to overcome (a problematic elbow found during his medical examination that set back his original deal), he re-signed with Houston again, in December 2016. 

Nineteen months later, the Astros promoted Pérez, age 22 at the time, from Double A to the majors, just in time for road games in Tampa, where he, his parents, his wife and his toddler son, Cionel Jr., were living. They were all there at Tropicana Field, anticipating his debut. It didn’t come. Pérez sat in the bullpen for two days and was returned to the minors without pitching.

Ten days later, on July 11, 2018, he was recalled, this time in Houston. He debuted in the eighth inning against the Oakland A’s, recording five outs while allowing one run. Only his sister and brother-in-law were able to get to Houston that night. But nothing could temper the moment, the energy, the butterflies. His family — including his mother, father, wife, 7-year-old son Cionel Jr. and 2-year-old daughter Genesis, who Pérez says is even more rambunctious than he was as a child — are living in Tampa as U.S. residents.

“I’ve sacrificed all of my life and seeing the fruits of my labor finally pay-off is great to see,” Pérez said. “I really feel like I’ve found a home. When I come in here, it really feels like home.” (Connoly-TheAthletic-Sep 30,2022)

TRANSACTIONS

Sept 2016: Perez signed with the Astros for $5.1 million, via scouts Charlie Gonzalez and Oz Ocampo. But a problem arose during his medical physical. Perez later ended up signed with the Astros for $2 million on December 6, 2016.

Jan. 23., 2021: The Reds acquired left-hand pitcher Cionel Pérez from the Astros for minor league catcher Luke Berryhill.

Perez has a 91-98 mph FASTBALL from the left side with a 70 grade. He has a 76-80 mph CURVE that is probably a 55 grade, on the 20-80 scouting scale. He manipulates that curve: he can sweep it across the zone early in counts, and he can also throw it with a shorter, harder downward break late in counts or against a lefthanded hitter. He also has a CHANGEUP that he improved in 2018 so he could remain a starter.

2018 Season Pitch Usage: 4-seam Fastball: 63.2% of the time; Change 6.8%; Slider 28.2%; and his Curve 1.8% of the time. Average velocity: 4-seam 95.7 mph, Change 87.9, Slider 84.8, and Curve 80.3 mph.

2019 Season Pitch Usage: 4-seam Fastball: 61.5% of the time; Change 10.6%; Slider 25.5%; and his Curve 2.5% of the time. Average velocity: 4-seam 95.5 mph, Change 88, Slider 83.3, and Curve 77.8 mph.

2020 Season Pitch Usage: 4-seam Fastball: 62.5% of the time; Change 2.3%; Slider 34.4%; and his Curve less than 1% of the time. Average velocity: 4-seam 95.1 mph, Change 87.4, Slider 83.9, and Curve 79.5 mph.

Cionel has good arm speed and is athletic. He has a conventional lefthanded delivery, that includes a twist at the top of the leg kick and some variation in arm angles.

Perez' stuff plays up because of his above-average control and command.

The Astros see Perez being a guy who can be in the rotation or come out of the bullpen. In relief, he can pitch multiple innings, if needed.

“It’s still unclear what path he’s going to be on—reliever versus starter. He can do both. We might keep him going as a starter, but we need a lefthanded reliever, so it could be a good fit for us," Houston GM Jeff Luhnow said, heading into 2018 spring training.

But Luhnow said the following heading into 2019 spring training. “He throws 97 (mph), and he has good stuff,” Luhnow said. “He’s demonstrated he can last six or seven innings, so I certainly don’t want to give up on that option too soon.”

2018 Season: Pérez spent 2018 bouncing between the Majors and Triple A, pitching just 11.1 innings for the Astros while allowing five runs on six hits for a 3.97 ERA and 6.34 FIP. Far from eye-popping. However, the 22-year-old was dominant during his stretches in Triple A that year, posting a 6-1 record and 1.98 ERA in 16 games while accumulating 83 strikeouts in 68.1 innings.

2020 Season: Pérez is 1-1 with a 5.74 ERA, 1.46 WHIP, 15 walks and 27 strikeouts over 26 2/3 innings in 20 big league games with Houston over parts of three seasons.

Over three Minor League seasons, the 5-foot-11 Pérez was 16-6 with a 3.65 ERA in 58 games (40 starts). He’s largely been used as a front-of-the-bullpen pitcher or called up when Houston needed a fresh arm.

In 2020, Pérez had a 2.84 ERA in seven appearances, but he also had a lackluster 2.05 WHIP. (M Sheldon - Mlb.com - Jan 23, 2021)

2021 Season:  In January 2021, Houston dealt Pérez to the Reds for a catching prospect. That didn’t work out so great for Pérez. Bouncing between the majors and the Reds’ Triple-A Louisville, Pérez finished 1-2 with a 6.38 ERA in 25 appearances for Cincinnati out of the pen. Based on that resume, the Reds decided to cut Pérez on November 24, 2021, and the Orioles claimed him immediately after.

2022 Season: Perez had a fantastic season with a 1.40 ERA, good for sixth-best in the Majors.  Estimators like FIP, xFIP, xERA, and SIERA say he is one or two runs worse than that but expecting regression next season does not change his results from this season.  Nine earned runs in 57.2 innings is outstanding any way you slice it.

Perez gave up just two home runs the whole year, but his other statistics aren’t quite as impressive, which is why the estimators are underwhelmed.  His 23.5% strikeout rate is a little above average, while his 9% walk rate is a little below average.  

More impressive is his total value, as Perez had 2.8 bWAR, which is elite territory for a reliever.  His 2.21 win probability added was 20th among relievers, which is quite good especially since most of the people in front of him are closers who pitch in higher-leverage situations (Bautista was ninth).  In RE24, which measures a player’s results compared to the base-out states, Perez ranked 16th with 13.40.

The lefty brings a hard 4-seamer and a wipeout slider, and he added a sinker upon joining the Orioles while shelving a changeup.  Even with just one breaking ball, Perez held both lefties and righties down.  He worked inside and outside with both kinds of fastballs, while his slider works in the zone and as an out pitch.  Sliders tend to do worse than curveballs and changeups against opposite-handed hitters because they move towards the batter, but Perez’s slider has a ton of vertical movement as well as horizontal movement.  

The Orioles like traditional diving sliders, which is probably why they claimed Perez in the first place.  Run values on his individual pitches also look quite good, as his 4-seamer had -10, slider -6, and sinker 0.   (Ben Schneider - Nov. 18, 2022)

2023 Season: A near-disastrous April and May was followed by some better results in every area other than ERA in June and July. Only after this did Pérez put together a couple of months where he showed why he was on the team.

Through the end of May, Pérez pitched in 24 games and had allowed 11 earned runs over a stretch of 20.1 innings. That’s a 4.87 ERA. In this same time, batters were hitting against him at Hall of Fame caliber. Pérez had allowed a .352/.426/.523 batting line across the first two months. It is almost unbelievable. Though there were reasons to believe he was having bad luck with a well above average .397 BABIP, he was also doing plenty to make it his own fault, issuing free passes to more than 10% of the batters he faced.

This was a reversion to previous form for Pérez. Challenges with command had plagued the parts of four seasons that Pérez pitched in the big leagues before the Orioles claimed him on waivers after the 2021 season. That year with the Reds, Pérez walked 20 batters in 24 innings pitched. This was his age 25 season and he was out of minor league options headed into 2022, so he was passed down to 2021’s worst team, the Orioles.

Only in 2022 in Baltimore did he get the walks under control, just a 3.3 BB/9 for the season after entering that year with a career BB/9 of 6.2. It is a big difference. Up through the end of July, the old Pérez was back.

Even as other aspects of his performance improved, including that Pérez did not allow an extra-base hit after the calendar turned to June, he was still prone to handing out a lot more free passes than you’d like to count him as a reliable reliever for a good team. June and July saw him walk another ten batters in 15.1 innings. That’s not good!

It’s not like the Orioles were giving out infinite chances to everybody who happened to be in their bullpen this year. Guys were getting optioned or designated for assignment throughout the season. Logan Gillaspie got 11 games and a 6.00 ERA and was sent packing. Austin Voth and his 5.19 ERA over 25 games were removed shortly after he returned from an injured list stint.

There were also guys whose season-long results were about as good or even a little better than Pérez’s - Bryan Baker and Mike Baumann particularly - who were sent to the minors while Pérez endured. It is still something of a surprise to me that the Orioles stuck with Pérez even as his WHIP over the full season was 1.556. Out of the 357 MLB pitchers who tossed at least 50 innings this year, Pérez was 326th in this category.

Part of that is because the team had the ability to send Baker and Baumann to the minors while it did not have that opportunity with Pérez. Another part is surely that Pérez had some value as a lefty specialist that those right-handers did not, holding lefties to a .213 average and .602 OPS for the season. Still another part is that Pérez maintaining a ground ball rate over 60% meant that at least whatever other problems he had, he wasn’t giving up home runs. His 3.54 ERA was 115th out of that same group of 50+ IP pitchers.

What’s interesting about comparing Pérez’s quality 2022 season to his not-as-quality 2023 is that from the perspective of Statcast expected stats, they were actually quite similar. Last year, Pérez had an xBA (expected batting average) of .236; this year, it was .237. His actual averages allowed were .220 and .262, respectively.

In expected ERA, Pérez went from 3.62 last year to 3.69 this year. With xSLG (expected slugging) he had a big improvement from 2022 to 2023, dropping from .361 to .324. That was a lower xSLG than every other O’s pitcher except for Félix Bautista and Baker.

Pérez went through maddening stretches, and Baseball Reference WAR tagged him with a -0.3, but again, when it came down to his actual ERA of 3.54, Pérez was... fine? You’ve got problems if that’s one of your two or three best relievers, but for the 2023 Orioles, he wasn’t. Over the full season, he was maybe the fourth-best - and in September he was probably behind DL Hall too. (Mark Brown  Nov 14, 2023)

June 30-Aug. 25, 2019: Perez was on the IL with a forearm injury.

July 4-18, 2023: Perez was on the IL with left forearm soreness.

March 30, 2024: Pérez exited the 13-4 win over the Angels in the ninth inning due to lower back discomfort. The 27-year-old left-hander allowed two hits without recording an out, then he walked off the field alongside head athletic trainer Brian Ebel.

Manager Brandon Hyde said Pérez will be re-evaluated and he's "day to day as of right now."