My guess is that he's dealing with a tear. That being said, if he pitches into the playoffs and has surgery or he has it now, isn't that much different. The return time is typically 12-14 months with a return to effectiveness around 18 months. If he goes under the knife now, he's still likely out all of 2018 and if he goes under the knife in October, he should be fully back to himself by April 2019. I get his determination to pitch through it, but you can hurt other things if you favor a bad elbow