I would be stunned if he didn't have the surgery in the next couple days and try to come right after the All Star Break. This isn't just about this year. It is about the next nine years, including this one. If he was going to be lost for the whole season, I might think otherwise, but this is a no brainer to me.
They knew about his discomfort late last year, and, for whatever reason, did not have it looked at. They made a mistake then, don't make it worse now and put off the surgery.