The Buffalo Bills shook up their defense Wednesday by placing veteran Kawika Mitchell at middle linebacker and inserting rookie Ashlee Palmer into the starting lineup.

Palmer moves up into Mitchell's weak-side starting spot. Marcus Buggs, the second-year man who started the past three games in place of injured Paul Posluszny, goes back to the bench.

Defensive coordinator Perry Fewell gave a blunt assessment of his unit in the wake of the past two games, in which the Bills gave up a combined 472 rushing yards.

"We need help in the middle, and so I felt like that was Plan B if Plan A didn't work," Fewell said. "And Plan A wasn't working, so I had to go to Plan B."

It was asking a lot of Buggs to produce. He's a 223-pounder who was undrafted out of Vanderbilt last year. He saw limited action in just four Bills games last season.

Mitchell is 253 pounds. He played middle linebacker for Kansas City from 2003 to 2006.

"It's I feel a natural position for me," Mitchell said. "I enjoy making the calls and making the checks and all that. I'm excited about it. And it's not going to be that difficult."

"I take pride in the fact I'm in there during a time when we're having some problems," Mitchell said. "I feel like the mike [middle backer] has always been the one who takes the responsibility for all that. So I'm excited to be that guy."

Asked what Mitchell brings to the middle, coach Dick Jauron said: "Experience. It's a hard position to play. You've got to make all the calls. You've got to make all the adjustments. We've put a lot of pressure on Marcus. I'm certainly not putting it all on his shoulders. There's enough to go around, and as always it starts with me. But Kawika has been around the game. He's got a nice feel. He doesn't fluster. I think that might settle the thing down in there."

"We didn't react properly, and there were a lot of mistakes made on each and every play," Fewell said. "That was unacceptable."

"I don't think 470 yards is an embarrassment as much as getting your butts kicked," Fewell said. "The front [four] played pretty decent. You say, 'well how can the front play pretty decent with 250 [rushing yards]?' The front played pretty decent, but the support system behind the front did not play very well, and so we missed a couple guys. We missed Bryan Scott and Donte Whitner; that's part of the support system that doesn't allow that to happen. We've got to make some changes to get that right."

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The Bills got some good news on the injury front. Left tackle Demetrius Bell said he participated in most of Wednesday's practice and he expects to start against Cleveland on Sunday.

Bell, who missed the Miami game with a sore groin, officially was listed as limited in participation. Defensive tackle John McCargo (calf) and safety Jairus Byrd (hip) also were limited. Safety Bryan Scott did not practice but he was moving around much better on his sprained ankle. Defensive end Chris Ellis missed the Miami game due to the death of his mother and is expected to miss the rest of the week's practices.

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The Browns have a couple of key injuries. Kicker Phil Dawson, who booted a 56-yarder to beat the Bills last season, probably is out with a calf injury. He missed the past two games. Running back Jamal Lewis, who also missed the past two games with a sore hamstring, was limited in practice. Other starters who were limited were DT Shaun Rogers (foot), LB Kamerion Wimbley (shoulder), LB D'Qwell Jackson (hamstring), LB David Bowens (knee) and G Floyd Womack (ankle).

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Receiver Terrell Owens on rebounding from the Miami defeat:

"You just have to keep plugging away. We use each game as an opportunity to get better. Obviously last year, they started out well and didn't finish well, and it's not how you start, it's how you finish. Definitely, that's my approach and I'm hoping the guys take that approach as well.

"All I know is I feel very comfortable about this game this weekend," Owens said. "I feel like we're going to win, and I feel that way every game. For some reason I feel a little better about this weekend coming up, just by the attitude that I've been seeing here since we reported this morning, and I have a lot of confidence in the guys on the field. We just have to go out there and make it happen."