Antonio Brown arrives at the Raiders' practice facility, along with his agent, Drew Rosenhaus, after losing a grievance against the NFL over wearing his old helmet. (0:46)

NAPA, Calif. -- Oakland Raiders receiver Antonio Brown offered the most detailed -- and graphic -- description of his frostbitten feet yet.

It was on Tuesday night's episode of HBO's "Hard Knocks," when Brown took off his socks and shoes -- "Wanna see it?" he teased the camera -- to show the peeling soles of his feet.

"My feet are pretty much getting circumcised, right?" he said in the interview, which took place away from the Raiders' training camp facility. "Hopefully, my feet are born again and I frickin' can run faster. Feel sorry for me later. Thank you."

And while it has been established that Brown suffered the burn while vacationing in Paris in July, the seven-time Pro Bowl receiver confirmed earlier reports that it was the result of a cryotherapy mishap.

"I was trying cold therapy, they were covering my body and I got out and I felt my foot burning," he said. "So I was like, man, I felt a hot sensation. So the next 24 hours it swelled up, got really big, and I couldn't really walk or put pressure. The doctor came over, drained a little out. Scalpel the next day, frickin' scissors the next day, and just kind of let it leak all out. So as everything leaked all out, I was able to put a lot of pressure. Thankfully, my trainer was working me out; I can't be on my feet, so I'm crawling in workouts, just getting other stuff done and have everything get better.

"So now it's just new skin. I'm trying to get my feet used to feeling it, but I feel like I got a big patch of just open whoopee cushion, you know?"

Brown was not wearing appropriate footwear when he entered the cryotherapy chamber, a source told ESPN.

Brown, who lost a grievance with the NFL to wear his old helmet on Monday, returned to Raiders camp on Tuesday after being away for two weeks. He and his agent, Drew Rosenhaus, insisted the injury -- and not the flap over his helmet -- was the true reason he was away, seeking therapy that included laser treatment.

Neither, though, would go into more detail over how, exactly, the injury occurred, with Rosenhaus saying legal action might be pursued "possibly" against the cryotherapy lab.

Brown still was walking gingerly when he arrived at camp.

Raiders coach Jon Gruden was not sure if Brown would play in any of Oakland's three remaining preseason games. But when asked if he expected Brown to be ready for the regular-season opener on Sept. 9, Gruden said, "Oh, yeah."