Thursday was another practice day for the Silver and Black as they returned to the field at their Alameda facility.

Vincent Brown, Tarell Brown, Chimdi Chekwa, Brian Leonhardt and Menelik Watson did not practice because of injury, but after missing Wednesday's session recovering from a knee injury, DL C.J. Wilson returned in a limited capacity.

Sunday's game against the Bills will be significant to rookie LB Khalil Mack who played his collegiate football at the University of Buffalo, earning a multitude of awards during his impressive college career.

The No. 5 overall pick has proven to be a bright spot on the Oakland defense this season, recording three sacks, forcing a fumble, and blossoming into one of the team's best defenders against the run.

"Some guys are built to last and some guys are built for the short term and I think this guy [Mack] is a guy that is built to last," said Interim Head Coach Tony Sparano. "He takes care of his body, he goes a million miles an hour. He only knows how to practice one way and that's the way that he plays the game. Usually those type of players end up being pretty successful in this league."

Defensive Coordinator Jason Tarver also praised Mack's work on the field, but made sure to stress that it's the rookie's intangibles that make him special.

"This young man is so honest," Tarver said. "He'll tell you, 'Hey, I didn't know that,' or, 'I knew that, but I did this.' That honestly level is really amazing in a young man, so therefore you can fix things so fast."

He continued, "The trust level is way up, because as long as we're having honest conversations and working together, you feel like you can do anything together."

While Mack has had an impressive rookie campaign, he is still not satisfied with where he is as a player.

"There are a lot of things I need to work at," he said. "I need to work on my vision looking in plays, playing with my hands better, especially pass rush. There are just a whole lot of things I want to work on."

The rookie will have a good defensive line to take notes from on Sunday, as the Raiders will welcome the NFL sack leaders to O.co Coliseum.

"They're playing lights out," Mack said when asked about the Buffalo defensive line. "They're great as a group. I believe there's three of them that have more than nine plus sacks, so yeah, they're playing very well. You want to build that and be first in the league in sacks as a group. We're still aspiring to do that."

Mack and the Raiders will hold their final practice of the week tomorrow, and will then take on the Bills at 1:25 p.m. PT on Sunday in their final home game of the season.