Brent Yarina, BTN.com Senior Editor, March 7, 2015

Jim Harbaugh is a busy guy.

Between coaching football and staying busy on Twitter, whether it be tweeting Judge Judy or reviewing a rap album, the new Michigan football coach is all over.

That includes Oakland Athletics' spring training in Mesa, Arizona. Harbaugh joined Oakland's coaching staff for Saturday's exhibition game for the Los Angeles Angels, and there are plenty of pictures to prove it.

The competitive and hardcore Harbaugh is in full uniform, too. Of course, he's wearing his old No. 4, which he wore at Michigan and in the NFL, and has his pants rolled up.

Check out the photos below: