Browner has filed an appeal, per Albert Breer of NFL.com.
The 29-year-old was suspended for the final four games of last season for using performance-enhancing substances and eventually dropped an appeal.
Michael Silver of NFL.com initially reported that Browner was facing a suspension for another violation of the league's PED policy, but later corrected it. Browner denied that he was facing a suspension for PEDs on Twitter.
I'm not facing suspension for PEDs, it's sad that the NFL is reporting this...
— Brandon Browner (@bbrowner27) November 25, 2013
Browner isn't the only member of Seattle's secondary facing a suspension. The NFL Network's Ian Rapoport reported on Sunday that cornerback Walter Thurmond will be suspended four games for violating the NFL's substance abuse policy. He is dropping an appeal so he can return for the postseason.