Chicago Cubs activated left‑hander Caleb Thielbar from the 15‑day injured list before Tuesday’s game against Milwaukee, bolstering the bullpen. After 14 days sidelined with a left hamstring strain, Thielbar has a 3.12 ERA over 8⅔ innings. His return comes as manager Craig Counsell seeks to steady the crew amid a sliding streak that has dented the Cubs’ push for the NL Central lead.

To make room, the Cubs designated lefty Ty Blach for assignment. Blach, 39, had been called up from Triple‑A Iowa earlier in the season and pitched three scoreless innings in Monday’s loss, his major‑league appearance this year. Meanwhile, the rotation suffers: Matthew Boyd remains out after a meniscus surgery, Cade Horton is season‑ended with elbow surgery, and Justin Steele’s recovery stalled.

Cubs sit ahead of the Brewers in the NL Central but have slipped to a 3‑game slide and a 7‑of‑9 skid since their 20‑3 surge. With the bullpen reshuffled and the rotation weakened, the team faces a stretch. A return to form for Thielbar could stabilize late‑game pitching, but injuries to starters leave the Cubs vulnerable as the race tightens.