Budding Cubs ace Cade Horton has damage in the ulnar collateral ligament in his right elbow that will require season-ending surgery, manager Craig Counsell said on Tuesday.
Counsell didn't specify the exact procedure Horton would have and said no date for the surgery has been set.
The 2025 NL Rookie of the Year runner-up exited his start on Friday in Cleveland in the second inning due to discomfort in his right forearm and was placed on the 15-day injured list on Sunday.
Horton, 24, was a revelation for the Cubs last season, going 11-4 with a 2.67 ERA over 23 games (22 starts). He earned nine of 30 first-place votes in Rookie of the Year voting, finishing second to Braves catcher Drake Baldwin. Horton looked sharp in his first start this year, allowing two runs over 6 1/3 innings against Washington on March 28, but he lasted just 17 pitches and four batters into his second start, with his fastball velocity dropping noticeably from the first to second inning,
The Cubs' rotation has been plagued by injuries early this season: Opening Day starter Matthew Boyd is on the IL with a left biceps strain (though the team hopes he will require only a minimum stay) and left-hander Justin Steele is still recovering from elbow surgery he underwent last April, with an eye toward a return in the first half of this season.
Right-handers Javier Assad and Colin Rea will fill out the back of Chicago's rotation with Horton and Boyd on the shelf.