May 1: Kahnle has triggered the assignment clause, reports Ari Alexander of 7 News Boston. The Sox will know by Sunday whether another team is willing to carry him on the MLB roster.
April 30: Veteran right-hander Tommy Kahnle, currently pitching with the Red Sox’ Triple-A affiliate, has an upward mobility clause in his deal that he can trigger tomorrow, writes Christopher Smith of MassLive.com. The clause was reported at the time of Kahnle’s signing in Boston, but it still bears mentioning with the seasoned setup man pitching well in the upper minors at present.
If triggered, an upward mobility clause would push the Sox to make Kahnle available to all 29 other clubs. If any other club would put him on its major league roster, the Red Sox would either have to select Kahnle to their own 40-man roster or, if they’re not willing to do so, allow him to depart to an organization that would put him in the major league bullpen. Such clauses are common in minor league deals for veteran players.
Through the season’s first month, Kahnle has done a nice job trying to force Boston’s hand. The 36-year-old has pitched 8 1/3 innings out of the Worcester bullpen, allowing three earned runs (3.24 ERA) on eight hits and three walks. He’s fanned eight of the 36 batters he’s faced (22.2%), hasn’t allowed a home run and has done a decent job avoiding too much hard contact (88.3 mph average exit velocity, no barrels, 41.7% hard-hit rate).
Kahnle’s 92.7 mph average fastball would be the lowest of his career, although through the first month of the 2025 season in Detroit, he wasn’t much higher (93.1 mph). He sat 93.6 mph the rest of the way. It seems reasonable to expect Kahnle’s heater to gain a bit of life as he continues to build up this season, but the four-seamer is a secondary pitch for him anyhow; Kahnle is perhaps the foremost changeup specialist in the game. This season’s 59.5% usage rate on his changeup is actually a stark decrease relative to recent seasons. From 2022-25, Kahnle threw 79% changeups against just 18.7% fastballs with a very, very occasional slider (2.4%) mixed in to throw some hitters off balance.
Although he’s coming off a lackluster season with the Tigers — hence the minor league deal — Kahnle has a lengthy track record of success in the majors. He’s been hurt more frequently than he or the teams for which he’s pitched would prefer, but from 2016-24, the right-hander logged a combined 3.11 ERA, 31.1% strikeout rate and 10.1% walk rate in 271 2/3 innings between the White Sox, Yankees and Dodgers.
It’s not clear whether the Red Sox would be amenable to adding Kahnle to the big league bullpen. Relief pitching has been a strength in an otherwise disappointing season for Boston. Sox relievers have combined for a 3.67 ERA that ranks eighth-best in the majors. The only Red Sox relievers who can be optioned are Greg Weissert, Zack Kelly and Tyler Samaniego. Plugging Kahnle into the ‘pen would give the Red Sox a sixth reliever who cannot be sent down without being exposed to waivers.
The decision will belong to chief baseball officer Craig Breslow, but interim skipper Chad Tracy — who managed Kahnle for several weeks to begin the season — sounded amenable to the idea. Asked by Smith just yesterday whether Kahnle could help the big league club, Tracy replied:
“For a veteran of his caliber that’s been around, yes, he can help out. He’s been around the big leagues for a really long time. He knows how to pitch. He’s been here, he’s pitched in the playoffs. So absolutely can help out.”
If not the Red Sox, there seems to be a decent chance Kahnle could draw the interest of another club. Each of the Nationals, Cardinals, Twins, Royals, Angels and Astros have received a combined ERA of 5.00 or worse from their bullpen so far in 2026. The Phillies, Astros, Cubs and Marlins all have their closers on the injured list. Chicago’s Daniel Palencia is expected to return soon, but he’s one of six Cubs relievers on the shelf.
