its all legit concerns, he went down really hard.
I am not saying he can't recover, but it at least set his development time by about 1-2 years.
Instead of practicing and continue developing his game, he now has a few stages before he can continue where he left off
1) recovery
2) get back in shape
3) continue to develop his game
Not being able to practice and continue to develop his game
You don't want him to rush his recovery and re-injure himself again but we won't know, till another 2years or so.
if he would lose athleticism, speed/quickness, and the how it will affect the mental part of his game...