BRADENTON, Fla. — Jim Harbaugh’s Rolodex is loaded. That’s no secret.

He talked Tom Brady and Derek Jeter into coming to Ann Arbor for signing day, he was invited by President Barack Obama to come to the State of the Union address and he’s apparently tight with Denzel Washington. For those reasons, Amarah Darboh and De’Veon Smith say that Harbaugh is an A-list celebrity.

But when former Michigan defensive coordinator D.J. Durkin left for Maryland, Harbaugh’s star-studded Rolodex wasn’t going to do him any good. After all, Don Brown wasn’t in it. That didn’t stop Harbaugh from looking up the number of the defensive coordinator of the nation’s top defense.

Lucky for Harbaugh, Brown had heard of Michigan, despite all of his time spent in the northeast. Brown answered Harbaugh’s call. Hours later, he had the job.

“I think obviously Michigan provides you an opportunity to play at the very, very highest level,” Brown said. “I just felt like it was — I’ve been in New England most of my career — an opportunity I did not want to pass up for sure.”

Brown and Harbaugh had some of the same friends, but their paths never crossed.

Still, Brown liked the fact that Harbaugh had been so successful in rebuilding programs at the collegiate and professional levels.

“What (Harbaugh) has been able to do at all his stops, I just felt like, where else would you want to have the opportunity to be a defensive coordinator?” Brown said. “He’s just such a solid, fundamental, philosophical approach guy. It didn’t take long to see that this was the type of environment I felt good about.”

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Brown joined Michigan in December, which gave him time to watch film for a couple weeks during the dead period, go to the Citrus Bowl and join Michigan’s recruiting frenzy in January.

He was a major factor in Michigan landing one of the nation’s top recruiting classes, which is loaded with four- and five-star defensive prospects. As part of Harbaugh’s unconventional — but successful — recruiting circus, Brown saw the positive qualities he had heard about Michigan.

“(Harbaugh’s culture) is very serious in nature about the game of football, but at the same time, the guys have fun,” he said. “Really, really quality group of young men, fun to be around. I’m a big guy on trust, and just my initial impressions, which I think go a long way as you’re sinking your teeth into this thing with the amount of time you spend with people, just a really quality group of guys from a character standpoint.”

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Brown’s situation at Boston College was much different from the one he inherited at Michigan. Even though Brown led the nation’s top scoring defense, the Golden Eagles still didn’t win a single game in the ACC. Only three Power Five schools scored less than Boston College did.

The demands put on his defense were great in a weekly basis. Michigan, on the other hand, finished ninth in the country in time of possession. Part of that was Harbaugh’s offensive overhaul, and the other part was Michigan’s third-ranked defensive third-down conversion percentage.

Brown’s group was actually first in that category. He accomplished that feat without the aid of a single four-star recruit. At Michigan, he’ll have established All-Americans like Jabrill Peppers and Jourdan Lewis to work with, not to mention consensus No. 1 recruit Rashan Gary, who will join the team this summer.

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It’s early, but so far, Brown likes what he sees from his new unit.

“Great group of guys. I think our athleticism is there,” he said. “We’re developing at a couple of positions, but I love their enthusiasm, I love their energy, I love their athleticism. But we haven’t put the pads on yet.

“As you know, that separates the men from the boys.”

Harbaugh likes what he inherited, too. After Michigan’s first practice on Monday, he told a story about how Brown peeled the paint off the walls during a team meeting. Harbaugh called him “a ball of fire” and said that he’s an intense man.

It doesn’t take long to watch Brown in practice to see what Harbaugh is talking about. Even though the team is still practicing without pads in the first week of March, no Michigan coach is as animated as Brown.

He wouldn’t mind if his defense embodied that come September.

“There’s two ways to play this game and it involves pressure,” Brown said. “One you apply it, and two you feel it. I’m not big on the feeling it so we’re gonna apply it.”