Chicago Cubs ace left-hander Justin Steele will have reconstructive elbow surgery and miss the rest of the season, manager Craig Counsell said Sunday.

It was not yet known if Steele would need full Tommy John surgery or just a partial repair, according to ESPN.

Steele, 29, is just two years removed from being an All-Star selection and finishing fifth in National League Cy Young Award voting in 2023, when he went 16-5 with a 3.06 ERA in 30 starts.

Steele was 3-1 through four starts this season, with a 4.76 ERA and a major league-leading five home runs allowed through 22 2/3 innings. His most recent outing saw him toss seven shutout innings with eight strikeouts and just three hits.

In five seasons with the Cubs, he has gone 32-22 with a 3.30 ERA in 102 games (91 starts), throwing 517 strikeouts and 155 walks in 506 2/3 frames.