He's 2 inches shorter, 15 pounds lighter, and his feet aren't as big, either.

Nevertheless, Marcus Buggs will step into the large shoes of middle linebacker Paul Posluszny on Sunday when the Buffalo Bills play their home opener against the Tampa Bay Buccaneers.

The 6-foot-1 1/2, 238-pound Posluszny is out for roughly the next six weeks due to a broken arm.

The fact the 5-11, 223-pound Buggs has been in the Bills' system since the start of last season gives him a good chance to succeed, Bills coaches say.

"I do think the guy behind [Posluszny] is very capable of coming in and doing a yeoman's job," said Bills defensive coordinator Perry Fewell. "Buggs can run the defense. He takes command of the huddle. He's a smart player. He can be a presence in our defensive front. He's not Paul Posluszny, though."



Buggs was signed by the Bills as an undrafted rookie out of Vanderbilt last May. He made it onto the practice squad to start last season, then was activated to the 53-man roster in October when John DiGiorgio got hurt. Buggs appeared in four games as a special-teamer before going on the injured-reserve list with a high-ankle sprain.

This summer, he beat out seven-year veteran Pat Thomas to win the backup job behind Posluszny. DiGiorgio wasn't in the mix, because he still was recovering from a knee injury.

"I'm ready for the opportunity," Buggs said. "I'm totally confident in myself that I'll be able to handle it."



The Bills acknowledge the big-time talent of Posluszny, the 34th pick in the 2007 draft, will be missed.

"It's going to be a major loss," linebacker Kawika Mitchell said. "He's a captain of our football team. He's been playing extremely well. People are going to have to step up to take his place, make sure the communication is good, because him being the mike linebacker, everything comes through him. It'll be a lot of weight on Marcus Buggs' shoulders. But me and Keith [Ellison] and whoever else is in there will help him out. I think he'll be fine."



"When you lose your captain and the guy who's the quarterback of your defense, it's definitely a blow to your club," Fewell said.

Vanderbilt is more well known for producing doctors than football players. Buggs graduated from the school with a degree in human and organizational development. Fewell said Buggs can handle the mental challenge.

"He's more than capable of running the defense," Fewell said. "I may not be as complex as I'd like to be, just so he can play fast and not have to think as much. But he's more than capable of getting us into the checks and some of the things we'd like to do."



Buggs practiced last season at outside linebacker. He moved to the middle at the start of this spring's practices.

"There's more responsibilities getting the play called to the defense, getting the defense lined up, getting everybody set and ready to play the play, making checks throughout the play according to formations," Buggs said. "The vocal part is the biggest change, having to know all those things and being able to communicate them out in time for everybody to play the play."



"In the preseason when we evaluated him, he had some really strong football games for us, and he played better as the preseason went on," Fewell said. "I don't anticipate any lack of production as far as he's concerned."



While Buggs is Plan A in the middle, the Bills could try another option on some downs. Keith Ellison is capable of working in the middle, too. He could get some snaps, with rookie Nic Harris stepping up to Ellison's outside spot.

The Bucs figure to try to challenge the stoutness of the Bills' run defense. Tampa rushed for 173 yards Sunday in a 34-21 loss to Dallas. Cadillac Williams rushed for 97 yards on 13 carries. Derrick Ward rushed for 62 on 12 carries.

"They play aggressive," Buggs said. "The line blocks aggressive, the running backs run aggressive. We have to come out and be more aggressive on Sunday."