Teams typically have film review and a light practice the day after the game. So that would've been Saturday for them, where I assume he would've taken the daily saliva test.It would depend on when the 21 days starts. We first heard about him testing positive when, Sunday? So if the 21 days is from the first positive test, and not the confirmation, then it depends on if the test was on Saturday or Sunday AND if the day of the first positive counts in the 21 days. If it does, and he tested positive Saturday then yes their game vs Michigan is day 22 and theoretically he could play. If the 21 days doesn't start until the day after the positive test, or he tested positive on Sunday, their Michigan game is day 21 and he would not be able to play.
If the 21 days starts after the 2nd positive, the confirmation, then it doesn't matter because it sounds like the results were received tuesday or late Monday. In either case in this situation he's out until a few days after their Michigan game.
They would've gotten back to Madison very early in the morning Saturday. So let's just assume it wasn't a party or celebration gathering that night, with film/practice let's say in the late morning or early afternoon.
Perhaps he somehow/somewhere contracted it in the process of travel to or from the game. Airports? Hotel? Food service staff?
QBs and kickers usually go to the stadium early, in a separate van from the rest of the team. Van driver?