That means he becomes an unrestricted free agent. He is free to sign with any club, including the Redskins.
Westbrook, a Washington, D.C., native, completed his third season on the Redskins. He also spent the 2007-08 seasons on the Redskins' practice squad.
Last season, Westbrook played in 15 games as a reserve cornerback and special teams player. He logged 10 tackles, four passes defended and one forced fumble on defense.
Serving on punt and kick coverage units, he had eight tackles, tied for fifth-best on the team.
Westbrook, the brother of former Philadelphia Eagles standout running back Brian Westbrook, earned a practice squad spot on the Redskins as an undrafted rookie in 2007. He worked his way onto the roster two years later.