Thomas was placed on injured reserve on Thursday, two weeks after he tore a calf muscle in a 36-14 loss at Jacksonville. The NFL rookie of the year in 2001, Thomas was used in third-down situations and as a backup in his second season in Buffalo.
Thomas had 36 carries for 89 yards and added 15 catches for 95 yards and a touchdown in 10 games, including two starts this year.
The good news is Lynch could be ready to return after missing the past three games with a sprained left ankle.
Lynch practiced on Thursday in full pads for the first time since he was hurt, leading coach Dick Jauron to say he's "optimistic" the rookie first-round pick will be ready to play.
Jauron noted that Lynch's ankle showed no signs of swelling after he had a limited role in practice a day earlier.
"I'm optimistic, too," said Lynch, who was hurt in helping the Bills secure a 13-10 win at Miami on Nov. 11. "It's getting better every day."
Lynch leads the team with six touchdowns rushing and, with another passing, has had a hand in seven of 13 touchdowns the offense has produced this season. He has 751 yards rushing, which still ranks 15th in the NFL.
Starting right tackle Langston Walker left practice because of an illness. Safety Donte Whitner missed practice due to illness.
To fill Thomas' roster spot, the Bills re-signed linebacker Leon Joe two weeks after the team released him. Joe, who appeared in five games with Buffalo this season, rejoined the team after he was released by Jacksonville on Friday, a few days after the team signed him.
Copyright 2007 by The Associated Press