"What a big thrill just to be at a big league park and being around the locker room, being in the skip's office," Harbaugh said before the game. "That's all very, very exciting."
This wasn't Harbaugh's debut in the first-base coach's box. That came last Spring Training, when he made a guest appearance on the A's coaching staff.
A noted baseball fan, Harbaugh set two goals for himself. First and foremost, don't let a Detroit runner get picked off first base.
"And then, secondly," he said, "don't get hit by a line drive."
Harbaugh successfully crossed the top item off his list in the first inning, when Tigers left fielder Tyler Collins stole second base despite an early send from the fill-in first-base coach. As for the second part of his plan, Harbaugh left the game unharmed after three innings.
"He was into it. I think he enjoyed it," Tigers manager Brad Ausmus said. "It was good to have him on the bench. There was a lot of discussion going on in the time that he was there. ... It was fun to have him. He was into the game."
Michigan's football team is holding its spring practice this week at nearby IMG Academy. The team had Wednesday off, so Harbaugh and a group of Michigan players hopped on a bus and reported to McKechnie Field late Wednesday morning.
Pirates manager Clint Hurdle, a lifelong Michigan fan, welcomed Harbaugh to Pittsburgh's Spring Training home and spoke to Michigan's players.
"Clint's been a Michigan football fan and Michigan fan for 53 years," Harbaugh said. "He's a good man, a real good man."
"I like the way Jim does things," Hurdle said. "Obviously he's very aggressive, he's very creative and he can be a catalyst."
Did Hurdle offer Harbaugh any coaching advice?
"I told him just to keep sending the guys to second, let our outfielders try to throw them out," Hurdle said, smiling. "Because at the end of the play, someone would be happy. Either Ausmus would be happy or I'd be happy."
Harbaugh walked around the field before the game, signing autographs and taking pictures with fans. Just before Jeff Locke threw out the first pitch, Harbaugh shook hands with Pirates first baseman John Jaso. Then he stepped into the coach's box, ready to get to work.
"Just an attitude of gratitude to be able to do this personally and for our whole team to be ... here for the game," Harbaugh said. "And I appreciate Clint Hurdle and the Pirates' organization for helping us out and getting tickets."