The Cleveland Indians will be without star pitcher Zach Plesac for the foreseeable future ... and it's all 'cause the guy took of his shirt "aggressively."
For real.
Manager Terry Francona just made the bizarre announcement Tuesday ... saying Plesac broke the thumb on his throwing hand undressing earlier this week -- and is now going straight to the injured list.
"He was, I think, probably rather aggressively ripping off his shirt and he caught it on his chair,” Francona told media members.