The Seattle Seahawks signed former San Francisco 49ers cornerback Perrish Cox on Tuesday, shortly after the NFL announced that cornerback Walter Thurmond had been suspended four games due to a violation of the league's substance-abuse policy.

The Seahawks also are considering placing cornerback Brandon Browner on injured reserve because of his groin injury, league sources told ESPN NFL Insider Adam Schefter. Browner was not expected to be available until mid-December, coach Pete Carroll said last week.

Browner also is facing a one-year suspension from the NFL for violating its substance-abuse policy, league sources have told ESPN. Browner, who has already had his appeal hearing on the matter, missed the final four games of last season for violating the league's PED policy.

San Francisco released Cox (5-foot-11, 189 pounds) this month. The 26-year-old corner had two tackles in nine games for the 49ers this season. He started nine games for the Denver Broncos in 2010 but sat out the 2011 season after he was accused of sexually assaulting a woman at his apartment in September 2010. He was acquitted of the charges in 2012 and signed with San Francisco later that year.