White Sox' Jordan Leasure Undergoes UCL Surgery, Expected Back for Spring Training 2028

White Sox reliever Jordan Leasure underwent UCL reconstructive surgery a few weeks ago, the club announced, per Scott Merkin of MLB.com. He is expected to miss the entire 2027 season and is targeting a return for the start of Spring Training 2028 — making this effectively a two-year absence, per the announcement as relayed by Anthony Franco of MLB Trade Rumors.

Leasure had been limited to 18 appearances this season, initially shut down in late May with what the team diagnosed as a flexor strain. That diagnosis, it turns out, also involved ligament damage that required the reconstructive operation. He had attempted to pitch through elbow discomfort before being shut down.

The backdrop

The injury lands against a notably different organizational backdrop than it might have a year ago. The White Sox have surged to 8 games over .500 and carry a magic number of 25 to clinch the AL Central — a team that started 2026 at 6-13 and 7-14 now finds itself in a legitimate pennant conversation. Leasure's absence doesn't alter any of that in the short term; it was already apparent he would not return this season.

His 2025 campaign is worth remembering as context for what the club is losing over the longer arc. Leasure tossed 64 1/3 innings of 3.92 ERA ball, led White Sox relievers with 80 strikeouts, worked his way into leverage situations, and picked up seven saves. This season was a different story — 14 runs allowed across 18 2/3 innings, with a stretch on optional assignment to Triple-A — but the 2025 version of Leasure was a genuine bullpen asset.

What happens next

Leasure will finish the year on the 60-day injured list. Per the announcement, the White Sox will need to either reinstate him to the 40-man roster or place him on waivers at the start of the offseason. That roster decision will arrive at a moment when the organization is also managing other moving pieces — the club recently added outfielders Tommy Pham and Jake Cave — and is reportedly pursuing a long-term extension with Munetaka Murakami.

The 2028 Spring Training target is the stated expectation, but the material offers no further timetable detail beyond that.