Then those 23 go on to infect a significant portion of the rest of the team and all of them go on to infect other people at the school, and then it spreads out to the community at large. If it's only Clemson, and only now, well before the season where they can isolate and be ready before the season. If not, then a school would be foolish to play games with such a high rate of infections and another school would be foolish to play them. A lot of the southern states didn't get hit as hard initially and reopened more quickly and are now seeing rising rates. Florida could be the next New York and football, but it's nature isn't a social distancing kind of sport. Yes, these are young, well conditioned athletes, and most should not have any long term effects. But all it takes is one death for the lawsuits to start. Not to mention while the athletes might do okay, their families and other people they might give it to might not do so well.
Not saying there won't or shouldn't be a football season, but if these numbers are not an outlier and continue as the season approaches, there won't be a season.