The Red Sox found their replacement for Kenley Jansen, in another veteran arm: Aroldis Chapman. Boston added the 36-year-old lefty on December 3 after Chapman turned into a good season with the Pittsburgh. It was a year that saw the veteran lefty strike out almost 100 batters and overwhelm hitters with triple-digit heat.
A Look at Chapman
The Pirates signed left-handed reliever Aroldis Chapman last winter after a resurgant 2023 campaign, one that saw him strike out over 100 batters and earn a second World Series title with the Rangers. And yet again, Chapman was thrust into important situations as one of baseball’s most difficult pitchers to face.
The 36-year-old finished ninth in total strikeouts (98) last season among relievers. Chapman earned 14 saves — nine of which came last September — last year, as the ex-Pirate became the team’s go-to reliever late in the season, after Pittsburgh ultimately pulled David Bednar from the closer’s role.
In that role, Chapman pitched relatively well. Last September, Chapman gave up six earned runs over 10 innings and 11 games, although four of those came in a blown save versus the Nationals on September 7.
Chapman re-gained velocity lost in the 2023 campaign and he maintained his status as a hard-thrower again in 2024. Sure, the average velocity on his four-seamer and sinker were down over one MPH last season. However, his four-seamer movement (17.2” IVB) was very much there and the sinker regularly hit triple-digits.
The lefty was one of two pitchers in Major League Baseball to throw a pitch at 105 MPH, the other being Ben Joyce of the Angels. Chapman hurled a 105.1 MPH sinker at Manny Machado last August.
That velocity, as one would expect, leads to a lot of whiffs and weakly-hit baseballs. Chapman finished with Whiff% and Chase% rates well above 30%, which put him above league average.
The one weakness Chapman’s had throughout his career is keeping his mechanics together. He has a delivery prone to overthrowing, which can lead to missing spots. Last season, Chapman had a 14.4% BB%.
Per reports, the Red Sox gave Aroldis Chapman a one-year deal worth $10.75MM.
Analysis
With Kenley Jansen no longer in Boston, Chapman fills a hole in Boston’s bullpen. The left-hander proved that while Chapman is still prone to blowups on the mound, the 36-year-old — who will be 37 come February — can still overwhelm hitters with velocity.
Chapman joins a Red Sox bullpen that was highly effective last season. Offseason acquisitions Justin Slaten and Greg Weissert both posted sub-4.00 FIP figures. Slaten, a 2023 Rule 5 Draft pick, was superb, as he struck out 58 over 55.1 IP thanks to two good breaking balls and an extremely tough-to-hit, rising fastball.
The Red Sox also have relievers Brennan Bernardino, Zack Kelly, Cam Booser, and Liam Hendriks — who missed all of 2024 due to Tommy John surgery recovery — under contract.
We’ll see which reliever will replace Jansen as Red Sox closer in 2025. However, one obvious perk of adding Chapman — aside from not handing out long-term money to another free agent reliever — is that he has an arsenal that no one else possesses.
Make sure to check out our looks at other recent free agent signings, including the Rangers’ pickup of Kyle Higashioka.