COSTA MESA, Calif. -- Just when you thought Los Angeles Chargers defensive end Joey Bosa, heading into his sixth season, couldn't do anything to surprise you anymore, he comes up with this: A media day photo with a very small (and terrified) dog in a baby stroller.

"That's what he came up with?" said running back Austin Ekeler.

No, it's not his dog. He once said to a colleague, "I can barely take care of myself, much less a dog."

It is part of the Chargers' "Doggie Draft," an initiative to get shelter dogs adopted.

"It suits him," said someone perusing the photo.

Or, as another colleague mentioned, watching Bosa run around several years ago frantic to find his helmet (it was in his locker): "It's just Joey being Joey."

"no i can't come. there's a picture of a dog in a stroller with joey bosa" pic.twitter.com/n9bu1GuffI

— Los Angeles Chargers () June 15, 2021

Bosa is a sort of enigma, until he gets on the field. There, he wreaks havoc with anyone in his way, recording 7.5 sacks and 29 solo tackles in 2020 despite myriad injuries.

At Chargers mandatory minicamp this week, he spent a good deal of time stretching with an elastic band, taking his time to work out his muscles. Then he picked up his helmet and sprinted over to his position group to continue to learn the new defense put in by a new staff which will change the scheme to a 3-4 from a 4-3.

"It's been tough for me the last couple of days," Bosa said. "But it's an adjustment. There's a lot more to this defense than I've ever been part of before."

Which is saying a lot for a three-time Pro Bowler ranked among the top defensive ends in the league. It's especially telling following a 2020 season, where he estimates he suffered 15 different injuries.

"Luckily a lot of them were just a swollen ankle, my shin and my triceps," he said. "The concussions -- there are no effects that I've been dealing with. I'm feeling good, nothing from last year."

Saying he'd only played in a 3-4 scheme a few times, Bosa admitted he'd have to work on his two-point stance and that he loved "being able to see the whole field" as he did.

That said, it is an adjustment that new head coach Brandon Staley believes Bosa, an Ohio State grad, will catch onto quickly.

"The thing that he does best is rush the passer," Staley said. "You can see why he is such a premium rusher when you're around him in person, with his hands, his quickness. His ability to process quickly on the move. ... We're certainly still learning him and he's learning us. Hopefully through training camp, we can really figure out exactly where that sweet spot is for him."

Bosa, who has 47.5 career sacks, signed a five-year extension worth $135 million last summer after being the third overall pick in the 2016 NFL draft.

Once he figures out the defense, he expects to record a lot more of those sacks.

Soft and unassuming before he takes the field, he becomes -- as he says -- "an animal" once the whistle blows. It's something that runs in the family.

His brother Nick, recovering from a torn ACL at the beginning of last season, comes to town with his San Francisco 49ers teammates in August for joint scrimmages against the Chargers.

"I'm sure my mom and dad are over the moon," Bosa said. "It will be fun."

Beyond that, Bosa seemed fired up for the season after just two days of mandatory minicamp. Training camp starts July 27.

"We got everything we needed," he said. "It's exciting. I don't want to get too carried away, but it's exciting."

Joey being Joey.