Michigan's secret about Bob Shoop leaked out and they had to release a statement prior to Jimmy's press conference. The gist of it is, Bob is coaching from home and the rest is confidential. He is working through Zoom.
So this could mean a few things: 1 - he is not allowed in Schembechler Hall for some dust up with a coach or something? 2- He has COVID, 3- another health issue with him or his family. 2 or 3 seems more likely for a sport that is all about contact and I can't see some fight would keep a coach home unless is was very egregious.