CLEVELAND — Red Sox closer Aroldis Chapman is 16th all-time in saves with 339, just two behind Hall of Famer Rollie Fingers (341).
The 37-year-old lefty has done the job for a long time, recording his first save more than 14 years ago. Chapman thinks teammate Justin Slaten can do the job for a long time, too.
“He has the ability to do it,” Chapman said through translator Carlos Villoria Benítez here at Progressive Field. “His command is very good. His velocity is very good as well. And I feel like every pitch he throws is very nasty.”
The Red Sox have to look no further than their 2025 roster for their closer in 2026 and beyond. The 27-year-old Slaten hasn’t allowed a base runner in eight of his 11 outings. He hasn’t given up a hit in nine outings.
He’s also already doing the job part-time. Manager Alex Cora has saved Slaten for the ninth and used Chapman to pitch the eighth twice based on matchups. Slaten also recorded a save on a day Chapman was unavailable after the closer pitched three of the previous four days.
Slaten has converted all three save opportunities he has received. Chapman is 4-for-4.
“Getting an opportunity to go out there, close the game out, I think it’s one of the more exciting things in all of baseball,” Slaten said.
Slaten has a 3.03 ERA, 0.95 WHIP, 13 holds and five saves while limiting opponents to a .208 batting average in 55 outings (65 ⅓ innings) since Boston selected him in the Rule 5 Draft in December 2023.
“I would say it’s something that everybody aspires to,” Slaten said about closing. “I mean, I had this journey of being a starter in the minor leagues where it’s like, ‘Oh, I want to be a starter in the big leagues.’ And then when I got moved to the bullpen, it was like, ‘OK, the pinnacle of that would be closing big leagues games.’
“So I think it’s … the role that everybody would want to have,” Slaten added. “But it’s not something that I’ve set my eyes on as this end-all, be-all.”
Slaten described Chapman as being “adaptable.”
“I think that’s super, super important in this game to be flexible and adaptable,” Slaten said.
Some closers have difficulty when they are asked to do anything else besides pitch the ninth in a save opportunity.
Chapman has stayed successful in different spots. He actually has more holds (37) than he does saves (24) since the start of 2023.
“For him to be that adaptable, it really just kinda speaks to the player and teammate overall that he is,” said Slaten, who wants to be as flexible if he’s ever given the chance to be a full-time closer.
Chapman added, “It doesn’t matter when you pitch. I feel like if you’re in the eighth or the ninth, it really doesn’t matter as long as the team wins.”
The staff met with Slaten and Chapman before the regular season opener in Texas and made both relievers know Chapman might pitch the eighth inning that day.
“We talked about, ‘Hey, if this part of the lineup’s up in the eighth inning, that’s gonna be you (Chapman)‚‘” Slaten said.
That was how it played out. Chapman faced Texas’ 2-5 hitters in the eighth. Slaten closed it out with a perfect ninth inning against the 6-8 spots in the lineup.
Slaten transition from starting to the bullpen at Double A in 2022.
“I had a couple rough years as a starter,” he said. “I think that kind of played into it where it was like, let’s see if making a switch from starting to the ‘pen can kind of just change things up, give it like a fresh new coat of paint pretty much.”
Slaten was in the Rangers system back then. Texas drafted him in the third round in 2019 out of the University of New Mexico.
“There wasn’t any extensive talks about, ‘Hey, this is what we’re gonna do and this is why we’re gonna do it,’” Slaten said. “It’s just one day they said, ‘Hey, we’re gonna start throwing you outta the pen’ — and that was that.”
High velocity, the ability to get hitters to chase pitches and strong command make Slaten a perfect fit to be a closer.
He has been up to 98.5 mph with his fastball this season. He’s in the 90th percentile among big leaguers in average fastball velocity (97 mph). Opponents have a .154 batting average and .125 expected batting average vs. his heater.
Slaten has a 36.7% chase percentage so far after ranking in the 97th percentile in chase percentage (34.9%) last year.
The righty has averaged just 1.5 walks per nine innings in the majors. He ranked in the 97th percentile in walk percentage (4.0) last year.
“It’s hard whenever you kind of start walking a bunch of people,” Slaten said. “It becomes contagious because now you’re trying to place the ball and whatnot. … I would say I’ve always been a guy that’s a strike thrower. And I think that, especially since I got here, it was not so much of like, ‘Hey, throw the ball in the zone.’ It was like, ‘You can get guys out in the zone.’ And just kinda gave me the confidence of being able to attack the hitters and be in the zone.”
Slaten already has been able to study under three top closers in Chapman, Kenley Jansen and Liam Hendriks, something he said has helped “a ton.”
“Not even from what they say but just watching and being around (them),” Slaten said. “Kind of seeing what goes into the process of getting ready to go out there. … I’ve talked about Chris Martin a ton, too. He’s another one where anytime that you have a guy that’s been in the league and has done it for so long, just being able to pick up on what they do on a day-to-day basis and how they wrap their mind around getting out there and pitching one inning — it’s special to have that kind of mentorship, leadership in the bullpen.”
