If he has surgery this week, he will be in a cast until probably January 1. I would think he could be 80-90% by March or April and go through some spring training drills at 3/4 speed (which I'm sure they won't take the risk). The problem is the last 10-20%. It seems like it is a full year getting your full strength, flexibility, and speed back. Now admittedly I didn't rehab like he will, nor did I need to get back on the same level. I tore mine at 25 years old playing Church league basketball. That was 1997 so maybe things have changed. It seemed like you recover the first 80% quickly, but it takes a long time to get the last 20%.
Edited to say he is doubtful to be full speed by August. Hopefully 95% by September 1, and 100% by October 1.