If he hasn't had surgery on his back (and he hasn't to my knowledge) then it is truly about meeting key milestones to reduce risk of re-injury. That can be very tricky and fleeting with back injuries and Im sure the last thing the staff or the training staff want to do is give an athlete chronic back issues at age 22 It can feel good one day and flame up the next...its all about getting to a point where endurance and physical activity dont weaken then muscle/structure around the injury...then go from there I have zero idea where he is in this process but he very well could be back tomorrow or never play again. Its a tricky situation