Photos: Jim Harbaugh coaches in Oakland A's spring training game

Bob Melvin signed a new coach- @CoachJim4UM Harbaugh played baseball at Paly- Melvin at Menlo-Atherton pic.twitter.com/umd0NzZXlp

— Dave Feldman (@Feldy) 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:

Clearly, it's good to be @CoachJim4UM. (Photos: @USATsportsImage) pic.twitter.com/KV79G1gEiN

— Michigan On BTN (@MichiganOnBTN) March 7, 2015

So, you see what @CoachJim4UM is up to today, @umichfootball fans? (Photos: @USATsportsImage) pic.twitter.com/uqK0GmUrMw

— Michigan On BTN (@MichiganOnBTN) March 7, 2015

.@CoachJim4UM, where?s the Sharpie? http://t.co/uOPv0JbvsI #GreenCollar pic.twitter.com/1vN7rG0g8v

— Oakland A's (@Athletics) March 7, 2015

Manager Bob Melvin and @CoachJim4UM's lockers. Coach Harbaugh will don green and gold for today's game. #GreenCollar pic.twitter.com/ymQhf9Vjfg

— Oakland A's (@Athletics) March 7, 2015

ICYMI: @CoachJim4UM, sporting the number 4, is helping coach today's #Athletics game. #GreenCollar pic.twitter.com/sSDn5VZOYW

— Oakland A's (@Athletics) March 7, 2015

That time when @CoachJim4UM coached first base for the #Athletics. #GreenCollar pic.twitter.com/rx99Qy5me3

— Oakland A's (@Athletics) March 7, 2015

Jim Harbaugh, your new #athletics first base coach. pic.twitter.com/GF0pywS8zl

— John Shea (@JohnSheaHey) March 7, 2015

Jim Harbaugh will coach first base for a couple of innings today for #athletics pic.twitter.com/ljUoU79hiH

— John Shea (@JohnSheaHey) March 7, 2015

Jim Harbaugh wearing No. 4 in #athletics camp: pic.twitter.com/lLWG3RllUf

— John Shea (@JohnSheaHey) March 7, 2015

Jim Harbaugh in green and gold for a day. #Athletics pic.twitter.com/SRCvS3vftl

— Joe Stiglich (@Joe_Stiglich) March 7, 2015

Jim Harbaugh lookin good in #GreenAndGold pic.twitter.com/drRePbNKRa

— Anisa El-Rabaa (@anisaelrabaa) March 7, 2015