If you've seen the stomach-churning photo of Antonio Brown's feet, you've probably also found yourself wondering the obvious: What the hell does that to your feet?

The Raiders' star receiver opened training camp on the non-football injury list and only has taken part in part of one practice so far in Napa. Brown's right foot reportedly is bothering him more than his left, and he went to a foot specialist in order to get the ailment that has caused layers of skin to peel off the bottom of his feet diagnosed.

So, what's the deal with AB's feet? Well, NBC Sports' Chris Simms has a theory. And while it's crazy, it's not out of the realm of reality for AB.

The Raiders star receiver's condition reportedly is due to him "entering a cryotherapy machine without the proper footwear," a source with knowledge of the situation told Simms.

Insane? Yep. Impossible? For Brown, not at all.

The wide receiver's insatiable work ethic has been well-documented on social media, and there's little surprise the star wideout would utilize cryotherapy in order to train as hard and as often as possible. 

 

Of course, one would hope Brown would know the proper attire if he frequently utilizes said recovery method.

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Now, there are different degrees of frostbite, and also a separate ailment known as uncomplicated trench foot. The latter is defined as "a type of non-freezing cold injury. It is a condition that develops when feet are cold and wet for a long time and affects the skin," by the CDC.

Per the CDC:

"The foot may be red, dry, and painful after it becomes warm. Blisters may form, followed by skin and tissue dying and falling off.  In severe cases, untreated trench foot can involve the toes, heel, or entire foot."

The last part would seem to jive with the photos we've seen of Brown's foot. It's possible Simms' source believed they are one in the same, since Brown's feet don't appear to have the look of frostbitten feet. But I'm not a doctor, so we'll leave the diagnosing to the professionals.

Simms also discussed the possibility of Brown having a condition called unidentified Buc fungus, which the former quarterback had when he was in Tampa Bay. 

Dr. David J. Chao, also known as @ProFootballDoc, doesn't buy the frostbite idea, but could see the ailment being of the fungal variety.

The mystery continues.