you said he doesnt have lots of money so he may have a hard time getting care for his knee...
If money isn't a thing (because its work comp), he should have plenty of access. We see professional athletes all the time on work comp. they're the best ones to treat because work comp reimburses 100%. If anything, therapy, doctor check ups (which are paid for in the original cost of surgery) should be a hot commodity; providers would be falling over themselves to treat him.
Gym memberships and personal trainers arent expensive either.
3rd string and practice squad guys are treated the same as big name guys. Out here they work out next to some of the biggest names in the NFL. Same gym. Same access to therapies. Same doctor pool to choose from. Different pocket books.