Brown, who has been out of Oakland Raiders practice, didn't wear proper footwear in a cryogenic therapy chamber, NFL Network Insider Ian Rapoport confirmed.
Chris Simms on Pro Football Talk first noted Brown's footwear fiasco.
"From what I was told, Antonio Brown is still day to day," Rapoport said. "(He) was away from the facility yesterday seeing a specialist. He's done this before. Did it a couple days ago. Remember, this all goes back to his foot, which he so disgustingly posted on Instagram, a couple weeks ago. Something that -- those of us who watched Hard Knocks -- is going to be a big storyline. When is Antonio Brown going to be back? When are his feet going to be better?
"As far as the backstory -- what led to this -- what I was told, talking to a couple Raiders people, basically the story that they are saying is that Antonio Brown used a cryogenic chamber without proper footwear and that is why his feet ended up the way they did. Certainly, some other questions medically, for his feet, how they ended up looking like that, how he trained through feet which are so badly injured he really can't continue to train. A lot of questions there. But at the very least, that is the story they are saying. Still day-to-day. Unclear when Antonio Brown is going get back out at practice."
At the very least, the foot issue is concerning from a rapport perspective with quarterback Derek Carr. At worst, it could affect the star receiver's regular season.
The lesson here, friends, is always wear recommended precautionary wear -- I'm looking at you, Frat Bro, about to enter a tanning bed without eye wear.