Updated

The Oakland Raiders have signed free agent cornerback Tracy Porter, adding an experienced starter to an untested unit.

General manager Reggie McKenzie announced the move Wednesday.

Porter played only six games last year for Denver because of problems with seizures and a concussion. He spent the previous four years in New Orleans. Raiders coach Dennis Allen was the secondary coach for the Saints in Porter's first three seasons.

His most productive season came in 2009, when he had four interceptions in the regular season and a Super Bowl-clinching interception return for a touchdown against Peyton Manning.

The other cornerbacks currently on Oakland's roster have combined for four career starts.