ALAMEDA -- The Raiders had four cornerbacks in for workouts Tuesday, in addition to defensive end Andre Carter and offensive tackle Patrick Brown, in the wake of their Week 2 loss in Miami.

Having lost starting cornerback Ron Bartell in the opener and likely losing Shawntae Spencer in Week 2 to a foot injury, cornerbacks Darius Butler, Cletis Gordon, Antwaun Molden and Kevin Thomas were evaluated by the personnel staff.

Carter, the former Cal star and onetime 49er, got a look during training camp also as the club monitors how he has progressed from a torn quadriceps which ended his season with the New England Patriots in 2011.

Butler, originally was a second-round draft pick by the New England Patriots in 2009.

Gordon has played for six different teams after starting with San Diego in 2006, while Molden and Thomas were last with New England and Indianapolis, respectively.

With Khalif Barnes sideline for an indefinite period with a groin injury, Brown was brought in for evaluation. He most recently was with the Minnesota Vikings but also spent time with Carolina and the New York Jets.

Oakland has an open spot on the 53-man roster after waiving Nick Guess, the long-snapper signed last week as an emergency snapper in case Jon Condo couldn't face Miami.

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