The San Francisco 49ers are keeping active even before the official start of NFL free agency. Just hours before the period opened, they signed defensive back Perrish Cox, who was recently released by the Denver Broncos. The deal was reportedly for two years.

Cox had a decent, but not necessarily standout rookie season in 2010. He played in 15 games and made nine starts. But he sat out the 2011 season due to some legal troubles and was likely deemed expendable for those very reasons. He was on trial for allegedly raping a woman who was incoherent. Although he was acquitted of those charges just recently, it appears the Broncos were no longer interested in dealing with him.

During that rookie year, he did show some promise. He made 54 tackles, forced two fumbles, had an interception and deflected 14 passes. His addition may make 49ers cornerback Carlos Rogers expendable. Rogers is coming off a breakout season in which he made six interceptions and started all 16 games.