It’s a harder decision than you think. One, do you isolate the players so they don’t bring back a potential infection into the rest of the university? And then how do you practically do that? Two, if an athlete tests positive, even if asymptomatic or mildly symptomatic, they have to be quarantined for 14 days at least, which is going to mess with rosters and practice (Imagine having 4 players test positive? Imagine if all of your coaches test positive and can’t coach).