DAVIE, Fla. -- Miami linebacker Zach Thomas was back on the Dolphins' practice field on a "limited" basis Wednesday. It's unknown if he'll play this weekend against the Oakland Raiders.

Thomas missed last week's game at the Jets because of a concussion he suffered in Week 2 against the Cowboys. The loss to the Jets was only the 14th game that the seven-time Pro Bowler was sidelined in his 12-year career.

"He went through all the walkthrough stuff and all the stuff at the beginning of practice and was there the entire practice," Miami coach Cam Cameron said Wednesday. "We're going to list him as limited. But it's a positive."

Cameron said Thomas' status would remain listed the same way "until almost game time." The winless Dolphins (0-3) host the Raiders (1-2) on Sunday.

Thomas participated in some non-contact drills with other linebackers in the first portion of Wednesday's workout, and teammate Channing Crowder -- who replaced him at middle linebacker last week -- said Thomas wanted to do more during practice than the Dolphins would allow.

"He's been hit in the head a bunch. He's probably always concussed, concussed 24-7," Crowder said. "He'll be back when he can."

Thomas played every snap in Miami's loss to Dallas on Sept. 16, but said he felt lightheaded in the locker room after that game. He complained of migraines last week and the team decided to keep him from the field.

But Thomas is lobbying for a different fate this week, Cameron said.

"It's not about that," Cameron said. "It's about the medical people just making sure to let it run its course. They felt awfully good about things so far. They wouldn't put him out there in pads ready to practice and going through a significant amount of practice if they didn't feel good about it."

Thomas has started 165 games for the Dolphins, more than any defensive player in team history, and led Miami in tackles 10 times in his first 11 seasons.

Copyright 2007 by The Associated Press