Been there done that.
Unfortunately I was playing hockey in Europe and tore my ACL, MCL & LCL in o e felled swoop.
If he follows his Orthopedic Surgeons rehab requirements, he could be near 100% when rehabbed.
DON'T RUSH YOUR REHAB OR PUSH TOO HARD!
I was in a full metal polio type brace for two years BUT surgical methodology have changed and as I said, I trashed three ligaments.
Not that it's good but thankfully it's just the ACL and he has at least a year of solid rehab he can utilize.
Best of luck Trevon!