Whoa. Has this been planned and I missed it?
For perspective, that's about the least invasive type of surgery you can do - arthroscopic is just a tiny incision, and cleaning out scar tissue doesn't cause any major disruptions like repairing a ligament or bone. I'd bet he'll be back to playing in 3-4 weeks.
It's never a good thing to have to miss training time with injuries though... here's hoping for a speedy recovery to stronger than he was before.