Baltimore Ravens defensive coordinator Dean Pees has admitted that he is concerned about his side's lack of depth at the cornerback position.

Starters Jimmy Smith and Lardarius Webb are locks for the roster ahead of the start of pre-season, but Pees has revealed that he is unsure who will play behind them and where.

Veteran Aaron Ross has been ruled out for the season, while young players Asa Jackson and Chykie Brown are battling it out to win the spot in the club's nickel defense.

Pee told reporters: "I don't think there's been more made of it. I think there is [real concern]. There's some depth, there's competition, but we've got to come out of this pre-season [and] somebody has got to rise up."

The Ravens were ranked 12th in overall defense last season.