CHARLOTTE — For Derrick Brown, football is the easy part. He knows what to do in an almost instinctual way, years of practice and a marriage of his mind and his passion taking over when he steps on the grass.

Walking again was the hard part.

"When they took my crutch away from me, I did have to relearn that," Brown laughed after the final day of Panthers minicamp on Thursday, recapping his return following knee surgery, after a Week 1 injury knocked him out for the rest of last season.

"Nine weeks of being on crutches, no weight bearing, and then trying to get on the treadmill, walk again. It felt funny, but huge strides from where we were then and now back out on the field running around with everybody.

"It's incredible. I never had something to do with like learning how to walk."

In the months since his injury and as rehab began, Brown has been open about both the challenges of sitting out an entire season after coming off a Pro Bowl year and the excitement around getting back on the field. What he has had to remind himself of, though, and often, is that the process doesn't stop just because he laced his cleats on again.

"I think it was just it was a mental game first," Brown admitted. "I was able to get back in the weight room and let myself know that I was strong enough to do it. That has been the progression the whole time; just be able to prove it mentally and then be able to do it."

Brown is still limited in practice as he continues to rehab from the knee injury. But simply being back on the field, allowed to participate at least at a walk-through pace again, feels like the start of something special in this phase of Brown's career.

"I was talking to A'Shawn Robinson yesterday, and he's like, you'll be good," Brown said. "I'm like, it's like you go to the playground. You got the basketball when you're a little kid, and they play with your ball, but then everybody else is playing. You have to sit out and watch. It sucks, but it's one of those things that you know it's just part of the process."

By the time training camp rolls around in approximately five weeks, the Panthers are hopeful to have their Pro Bowl defensive tackle back at full strength. Brown says he is "very close" and expects to be ready by camp as well, albeit with load management.

"Hopefully, in the next few weeks, I get cleared. So that's the goal," Brown revealed. "And then, at that point, it's just getting back in football shape and, you know, being able to go out there and play with a team; that's what's on my mind, to be honest."

That team, particularly that defensive line unit, looks much different than the one he left, thanks to Dan Morgan's work in the past calendar year. Robinson saw a huge increase in snaps as last season wore on, showcasing an ability to play every down. And in free agency this spring, the club brought in Tershawn Wharton from the Chiefs, Bobby Brown III from the Rams, and Cam Jackson in the draft.

Bolstering the interior specifically has helped the group stand out this offseason to Dave Canales.

"It's such a competitive, great group. We added guys in free agency. We added Cam in the draft. We added Jared Harrison-Hunt after the draft, so that whole group, the way they've been working, you look around, we're bigger, we're faster, and we got a lot of experience on that line. So I think it's one of the stronger points of our team in general."

And with that size and talent, the entire line has seen an uptick in intensity and focus.

"I feel like right now in our room we've got a bunch of selfless guys," noted Brown. so you know when you play with selfless guys that just want to come out and work every single day, then you know that's where you build that brotherhood.

"That's where you come in here, and you know it doesn't have to be one guy's show or the next, but when we get to go out to the field and play, I mean, I think that's where you start to get there. There's no drop off in play."

And when Derrick Brown returns to full strength, that play will continue to rise. It's why he's sticking around during his summer break, partly in preparation for the arrival of his baby daughter (due at the end of July) and partly because by the time training camp arrives, he wants to be ready.

"I'm not tied here because of rehab, but I do feel like I owe it to my teammates to be out there when we're here to take the field in September, so I'll be there."