Jameson Taillon is headed to the 15-day IL (retroactive to July 1) with a right calf strain, the Cubs announced Friday. Left-handed pitcher Jordan Wicks was recalled from Triple-A Iowa in a corresponding move.

Taillon injured his calf while running in a training session, Cubs manager Craig Counsell told reporters Friday ahead of the team’s series opener against the St. Louis Cardinals at Wrigley Field.

The righty was slated to start Saturday’s contest, which will now be a bullpen game. Counsell told media an opener would likely be announced following Friday’s game.

“This was just an unfortunate injury during training,” Counsell said of Taillon. “He was running and felt a grab yesterday after his bullpen. He’s gonna miss a pretty significant amount of time.”

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The move comes after Taillon’s start in Houston on June 29, in which he went 4.2 innings and allowed two earned runs on five hits. The right-hander struggled over June as a whole, posting a 5.57 ERA across six starts in 32.1 innings. His season ERA stands at 4.44 in 17 starts and 95.1 innings pitched.

Taillon is the third starter in the Cubs’ rotation to hit the IL during the 2025 season, after Justin Steele was ruled out for the season in April and Shota Imanaga, who recently returned from the IL, missed nearly two months with a hamstring strain. Javier Assad, who made 29 starts in 2024, has dealt with an oblique strain since February and has yet to see big-league action this season.

The Cubs now face another rotation conundrum, as they do not plan on using Wicks in Taillon’s place.

“He’s there to pitch in the bullpen — we’ll go from there,” Counsell told reporters of Wicks.

Wicks has pitched well in Iowa over his last three starts, posting a 1.64 ERA in 11 innings of work. He has a 4.06 ERA with 46 strikeouts in 44.1 innings pitched in Triple-A this season. Wicks dealt with his own injury issue in late May when he landed on the 7-day IL with a left hamstring strain. He was activated on June 19.

The southpaw struggled in his initial stint with the Cubs this season, allowing three earned runs on as many hits without recording an out on April 18 against the Arizona Diamondbacks. He made a two-inning appearance in the same series two days later, allowing two unearned runs on three hits across two innings. He was subsequently sent back down on April 21.

“We’ve got him healthy and he’s pitching well,” Counsell said of Wicks. “He’s just gotta come up here and attack the strike zone and get himself in favorable counts — I think that’s really important for him. Let the offspeed stuff be effective.”