An MRI performed on Raiders quarterback Bruce Gradkowski on Monday revealed a third-degree separation of his right (throwing) shoulder, according to a source familiar with the situation.

Coach Tom Cable hadn't received word of the results of the MRI by the time he met with the media for his weekly news conference, so he wasn't able to comment on the bad news he expected.

Gradkowski reinjured the shoulder Sunday against the Miami Dolphins in a 33-17 loss at the Oakland Coliseum. He was making his first start since Oct. 10, when a sack by San Diego Chargers linebacker Shaun Phillips aggravated the injury he first suffered Sept. 26 against the Arizona Cardinals.

Gradkowski missed the remainder of the Chargers game and the next four games while recovering from the third-degree separation, the most severe kind. He said after the Miami game that he felt comparable to the way he did after the San Diego game.

Sure enough, the results confirmed Gradkowski's fear that he had undone the progress from the previous seven weeks. The MRI also revealed other damage, though nothing as severe as the separation.

A third-degree separation typically involves the tearing of all the ligaments in the shoulder that hold down the clavicle, according to several medical websites, and takes weeks to months to heal completely.

Cable said earlier Monday that it's conceivable Gradkowski won't play again this season.

"If that is true, yes," Cable said of the prospect of not having Gradkowski again this season. "But we'll know more as soon as we kind of get this thing evaluated and see how serious it is this time, see if there's any more damage."

For now, Cable said, the Raiders are moving forward as if Jason Campbell is going to start against the Chargers on Sunday. Cable ruled out the possibility of giving No. 3 quarterback Kyle Boller a shot.

  • Campbell is 28th in passer rating (75.8) among starting NFL quarterbacks. Gradkowski is 32nd (66.3) out of the 33 ranked.

  • Cornerback Nnamdi Asomugha (ankle) also underwent an MRI on Monday after aggravating his injury against the Dolphins. The results won't be released until Wednesday. He missed two games with the injury that he first suffered Oct. 31.

  • X-rays on tight end Zach Miller's right leg revealed a deep bruise, Cable said. He suffered the "pretty severe" injury against the Dolphins and missed part of the game. Brandon Myers is the only other tight end on Oakland's 53-man roster.

  • Quote of the day: "Anyone who would think that would be very foolish. This is about winning football games. Period." -- Cable, when asked about the perception that he favors Gradkowski and managing general partner Al Davis is partial to Campbell

  • Wide receiver Chaz Schilens (knee/foot) is making progress after a recent setback, Cable said, and is expected to practice in a limited capacity.

    Schilens hasn't played this season while recovering from surgery on his left knee midway through training camp.

    He also aggravated a foot injury in practice Nov. 19. The left foot injury required surgery before last season -- he had a second surgery on the foot after the season ended -- began sidelined Schilens for eight games.

  • The Raiders face the most daunting schedule the final five games among the teams in contention for the AFC West title.

    The Raiders' five opponents are a combined 28-27 (.509 percentage), the first-place Kansas City Chiefs face teams that are 24-31 (.436), and the Chargers play teams that are 21-34 (.382).

  • Former NFL players Dan Marino and Shannon Sharpe are convinced Raiders defensive tackle Richard Seymour got off light by being fined $25,000 for hitting Pittsburgh Steelers quarterback Ben Roethlisberger in the face Nov. 21.

    On Sunday, they said Seymour's punishment would have been far greater had the openhanded blow been to the face of Indianapolis Colts quarterback Peyton Manning or New England Patriots quarterback Tom Brady.

    "They would have probably thrown him out of the league," Marino said on CBS's pregame show, of which he is a member. "Seriously. Richard Seymour has been a Super Bowl player. If he'd known that that was Roethlisberger behind him, he probably wouldn't have done it. He thought it was a lineman. But at the same time, I'm sure the fine would be higher if it was Brady or Manning."

    Sharpe said: "I totally agree with you, Dan. They completely changed the rules when a guy did a legal hit and put Tom Brady out for the entire season. If you go up and hit this guy knowing Tom Brady or Peyton Manning, they are the face of the National Football League, that's going to cost you a quarter million (dollars), and you're out of the league. You're going to have to apply for reinstatement."

    sundAY'S game
    Raiders (5-6) at San Diego (6-5), 1:05 p.m., CBS