ALAMEDA, Calif. (AP) Oakland Raiders safety Nate Allen practiced Wednesday for the first time since suffering a serious knee injury in the season opener.

Allen tore the MCL in his right knee during a Week 1 loss to Cincinnati. He was placed on injured reserve with a designation to return then spent the next six weeks working his way back.

While Allen - who signed with Oakland in the offseason after spending his first years with the Eagles- is cleared to practice, he won't be eligible to play until the Raiders face the Vikings on Nov. 15.

More from FoxSports

Oakland has three weeks to decide whether to add Allen to the 53-man roster or keep him on injured reserve.

The Raiders own the worst-ranked pass defense in the NFL while giving up more than 303 yards a game through the air.