MANKATO, Minn. – As if dark Oakley sunglasses and a black ball cap slunk down to his eyebrows didn’t give it away, linebackers coach Mike Singletary is keeping a low profile during his first Vikings camp.

Shortly after Tuesday’s walk-through, Singletary displayed the same quickness that helped him become a hall of fame linebacker, leaving through the side while everyone else used the front gates.

The embattled former San Francisco 49ers head coach is no longer declaring “I want winners!” from a podium. But if he has his way, old friend Leslie Frazier will become one as the Vikings’ first-year coach.

Singletary’s job, he says, is to intercept any distractions headed Frazier’s way.

“I might have the opportunity to do this again, but right now this is his moment, this is his team,” said Singletary, fired by San Francisco after two seasons and a 5-10 record in 2010. “I’d do anything for Les. He knows that.”

From their days together on the vaunted 1985 Chicago Bears defense, Singletary the fiery linebacker has played protector to Frazier the calm, composed cornerback.

If anyone tested Frazier in the locker room, Singletary said he’d tell them, “Don’t say anything to my partner.”

Since the Vikings hired him in January, Singletary has kept one eye on Frazier’s every move as half-friend, half-bodyguard.

“I feel like he’s been protecting me for the 30 years I’ve known him,” Frazier said.

So far, there’s been no reason for Singletary to intervene. Frazier always has been great at relationships, Singletary said, and managing a locker room and coaching staff comes naturally to him.

But Singletary knows the time will come. So he waits.

“I’m here to speak up if something’s not right,” he said. “Whatever it is, whether it’s on the field or in the locker room. I know what he wants, and I have to protect that. I’m here to help him build a winner, and that means having a disciplined, smart team with chemistry. Nothing can jeopardize that.”

Singletary has plenty of responsibility coaching linebackers, arguably the Vikings’ greatest strength because of Chad Greenway and E.J. Henderson. The Vikings will have a new, inexperienced starter at weak-side linebacker, likely Erin Henderson, whom Singletary tutors, and Frazier has leaned on Singletary’s experience on how to conduct team and coaching meetings.

Keeping his linebackers on edge is no problem, apparently. Greenway admits Singletary “scares you a little bit” at first.

Frazier and Singletary hardly have time for casual dinners together, but they often meet briefly at the end of each day to discuss what they observed on the job.

“I’m not a calm person,” Singletary said. “I’m a very vocal person, where he’s calmer. We can balance each other out that way.”

Singletary endured a turbulent last season in San Francisco that included reports of locker room discord and a sideline spat with quarterback Troy Smith. Instead of holding out for a defensive coordinator position, Singletary felt drawn to Minnesota through prayer and friendship.

“I don’t think he regrets where he is,” Frazier said. “I get the impression from everything he’s told me in what he sees in our players that he’s enjoying this experience. He’s moved on from San Francisco.”

But he hasn’t moved on from the hope of head coaching again. Despite admitting he could have handled things differently in San Francisco, Singletary said he “did the best I could with what I had.”

A few years watching Frazier’s back could open more doors.

“I have a long list of things I learned from that time,” Singletary said. “They are lessons I can apply to the future if I ever get that chance again.”