Raiders receiver Antonio Brown out indefinitely with injured feet

Aug. 7 (UPI) -- Oakland Raiders receiver Antonio Brown is out indefinitely after injuring his feet in a cryogenic therapy chamber.

Brown didn't wear proper footwear and sustained blisters on his feet, according to NBC Sports and NFL Media. Brown began training camp on the non-football injury list before returning to practice.

Brown remains out of practice.

Brown has 837 career receptions for 11,207 yards and 79 touchdowns since debuting in 2010. Brown played his entire career for the Steelers.

Brown caught 104 passes for 1,297 yards and a career-high 15 touchdowns last year.

Oakland opens the preseason Saturday against the Los Angeles Rams. The Raiders begin the regular season Sept. 9 against the rival Denver Broncos.