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Ravens linebacker C.J. Mosley knows he has to step up his game amid a rash of injuries to his defensive teammates. Rob Carr Rob Carr/Getty Images

The Ravens defense was carved up by Browns quarterback Josh McCown to the tune of 457 passing yards on Sunday and linebacker C.J. Mosley is happy to point the finger at himself for his role in the team's misfortune.

Baltimore's loss to Cleveland was the third game this season it has blown a lead in the fourth quarter, a fact not lost on Mosley.

"I'll point out myself," Mosley said via the team's official website. "Just like the last two losses, it's on the defense. We played with the lead for a while, gave up big plays, and at the end, we've just got to finish. We keep saying that, but we've got to do it."

The second-year linebacker received the worst rating of his young career from Pro Football Focus for his performance against Cleveland, struggling against the run and also in pass coverage. His inability to stay with Browns tight end Gary Barnidge on a third-down play in overtime resulted in a 19-yard gain, extending the drive that ended with the game-winning field goal.

Mosley, the runner-up last season for NFL Defensive Rookie of the Year, has 29 tackles, two sacks and three passes defensed in five games. He knows he has to step up with defensive leader Terrell Suggs lost for the season and pass rusher Elvis Dumervil now nursing a groin injury that forced him out of Sunday's loss.

"When I point out myself, certain players have got to do a better job at what we do," Mosley said. "We're disappointed, because we know what kind of team we are; we know how we work, and we're definitely better than 1-4. We've just got to put our foot down and prove that."