If that's it... it's almost what my son had last year... my son had to wear this shoulder harness that limits your movement but he should be able to play. My son said the biggest issue he had with the hardness was that it just ripped his hair out of his arm pits and chest.
If it's a CV joint issue.... likely done. They may try to go with a harness... but considering that he is a possible 1st day draft pick, he might ask to hang it up.