Wheeler underwent a successful procedure to clear out the blood clot near his right shoulder on Monday morning, but it's unclear when he could be back.

PHILADELPHIA — Phillies ace Zack Wheeler had surgery Monday to remove a blood clot in his upper right arm, and the team says a timeline for his recovery remains unknown. Manager Rob Thomson acknowledged the uncertainty, saying, “We don’t know,” when asked whether Wheeler would pitch again this season, or if the situation was career-threatening.

Philadelphia Phillies ace Zack Wheeler had surgery Monday to remove a blood clot in his upper right arm, and the team says a timeline for his recovery remains uncertain.