"Not to be a pessimist but ankle sprains take forever to heal and are easily reaggravated. I hope it is something else."
Where do you get your info. from? I had a number of sprained ankles in my athletic career and they were not that bad, at least they weren't for me. Of course they swelled up like beach balls and it was tough to walk and getting a skate on was impossible. But once the swelling went down, while there was discomfort,I played through it. If that is what it is, holding him out the rest of spring is the right move and by later this summer he'll be 100%.