''Not good,'' Shell said of Gallery's injury. ''He'll be out a couple weeks, at least. He has the same thing as Robert Thomas (had in training camp) and Robert Thomas was out quite a bit. He's a lineman so he's really using his legs a lot. (Trainer Rod Martin) said he thinks about 2-3 weeks.''
Gallery's injury is the latest blow for Oakland's besieged offensive line that has been under heavy scrutiny since getting beat for nine sacks in a season-opening 27-0 loss to San Diego last Monday.
Journeyman Chad Slaughter took all the reps at left tackle in practice Thursday and is expected to start against Baltimore. Slaughter's only other start came in the final game of the 2005 season when he shut down Giants defensive end Michael Strahan.
The 6-foot-8-inch, 340-pound Slaughter will get another test this week when he is likely to face Pro Bowler Terrell Suggs.
''Chad's a battler,'' Shell said. ''He's got long arms, which give him an advantage. Robert's arms aren't as long as Chad's. He's a big guy. He can get the guys before they can get to him. He can punch (block) pretty good.''
Shell said he briefly flirted with the idea of moving guard Barry Sims out to left tackle, his home for the last several seasons, but decided against it.
Cornerbacks Nnamdi Asomugha and Chris Carr were also held out of practice Thursday and are questionable to play against the Ravens. Linebacker Sam Williams also missed practice for the second straight day.
* The Ravens aren't coming into this game overconfident, according to linebacker Ray Lewis. While Baltimore shutout Tampa Bay and San Diego shutout Oakland, he doesn't think the Raiders will simply lie down.
"No, that's like a boxer watching a previous fight-somebody getting knocked out in the first round, and then they come in and take their opponent lightly and they get knocked out," Lewis explained. "We're not going to do that. We know the capability of the Oakland Raiders. Any time you have Randy Moss on the other side of the ball, you're going to have problems. You better be aware of where he is. Right now our focus is trying to get another win. [That is the] bottom line, no matter who they played last week or how they played."