Jim Harbaugh has been around football for a long time. There’s no shortage of people he can call for a recommendation. But his brother John, the coach of the Baltimore Ravens, is the one whose opinion he cares about most.

“Cares about Michigan football and me as his brother,” Jim said Thursday. “That was one recommendation I knew I could count on.”

So when Harbaugh went looking for a new man to head Michigan’s defense after firing Don Brown in December, he turned to his brother’s recommendation. With one of the most important hires of his tenure in Ann Arbor, Harbaugh hired Mike Macdonald, a 33-year old whose most recent experience was as the linebackers coach on John Harbaugh’s staff.

It’s a bold hire for a program in Michigan’s situation. The Wolverines’ defense struggled during the six games it played in 2020. There was an embarrassing home performance to a rebuilding Michigan State and a decades-long winning streak against Indiana snapped. Wisconsin, Rutgers and Penn State alike all took advantage in different ways, leading to a 2-4 record and a referendum on the program that ended in Brown’s firing and an extension for Harbaugh that cut his pay in half and lowered his buyout to $4 million and falling. All of it seemed to point towards issues in recruiting.

Now, as Michigan kicks off spring ball, it does so with an almost entirely new defensive staff led by Macdonald. Defensive line coach Shaun Nua is the only holdover from 2020. Maurice Linguist, who comes from the Dallas Cowboys, holds a co-defensive coordinator title. George Helow will coach linebackers, and former West Bloomfield high school coach and Michigan wide receiver Ron Bellamy is set to take over safeties after a last-minute shuffle.

Harbaugh described Linguist’s role as mostly based in coaching the secondary. It seems he’ll also take a lead on recruiting — his history at Texas A&M includes a resume dotted with top-100 commits and relationships in places like Texas and Georgia where the Wolverines haven’t been a major player of late.

“(Linguist) is a tremendous coach,” Harbaugh said. “Tremendous communicator.”

He sung the praises of the rest of his defensive staff as well, talking of how pleased he was this week when Bellamy and Helow changed their roles without hesitation following linebackers coach Brian Jean-Mary’s departure to Tennessee this week. “I told them, ‘That’s music to my ears,’ ” Harbaugh said. “And a tune you don’t hear all that often in today’s world.”

Ultimately, though, it will all come back to Macdonald — the first and most important hire Harbaugh made this offseason. 

“Mike is really good,” Harbaugh said. “Really smart. Right now, what we’ve seen on the field is putting in the systems, players understanding them, growing, lot of coaching going on, drill work, installation. On field coaching has been really good. Really pleased.”

Harbaugh declined to go into specifics when asked about what kind of system Macdonald would run. Unlike Brown, who came in with an established background and a system so well known that old playbooks can be found online, Macdonald has never been in charge of a defense.

In an appearance on Jon Jansen’s In the Trenches podcast, Macdonald spoke in generalities. Michigan will be “multiple” and “aggressive” he said. “We’re gonna play man, we’re gonna play zone. We’re gonna be complementary. But it’s how you play that makes the difference.”

“It’s definitely a different language, different front structures, different coverages, different blitz patterns,” Harbaugh said Thursday. “Hope it looks really good.”