The Raiders expect to be without Justin Tuck for some period of time -- and it could be longer than Raiders fans would like. Jeff Curry USA TODAY Sports

Justin Tuck underwent an MRI on his injured right shoulder after Sunday's loss.

The results were enough to turn a normally-upbeat Jack Del Rio into a cloud of gloom.

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"I think we'll know what direction we're going to go when we need to," the head coach told Jimmy Durkin of the San Jose Mercury News. "I'm not going to sit here and speculate."

Which means something is seriously wrong with Tuck. And now, Del Rio will have to decide to keep his veteran defensive end active or shut him down completely; safety Nate Allen already occupies the team's IR-recall spot.

Luckily, the Raiders drafted to cushion the blow of a loss like this. Rookie Mario Edwards Jr. subbed in for Tuck and looked promising against the Broncos.

His loss might be felt more from Monday to Saturday. Tuck is a locker room leader -- a Super Bowl champion who mentored Edwards Jr. and others.

He has 14 tackles, a sack, three passes defensed and a blocked PAT so far this year.

(h/t Contra Costa Times)

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