ORCHARD PARK, N.Y. (AP) — Size mattered to the Buffalo Bills on Friday after they spent the NFL draft bulking up their defensive line.

The Bills opened the second round by drafting Central Florida defensive tackle Torell Troup with the 41st pick. And they followed by drafting hulking Arkansas State defensive lineman Alex Carrington in the third round, 72nd overall.

The selections came as Buffalo attempts to shore up a porous run defense that finished 30th in yards allowed last season. The team's also making the switch to the 3-4 scheme under new head coach Chan Gailey.

"We felt fortunate we got some guys that will fit our defense and hopefully, we won't be knocked back 4-5 yards every time they run the ball," first-time general manager Buddy Nix said. "And if you're going to get big, you just about got to get big in the first three picks."

Going big was a departure from how Buffalo opened the draft on Thursday by selecting undersized speedster, Clemson running back C.J. Spiller with the No. 9 pick.

Troup is a run-stuffing tackle who's listed at 6-foot-2 and 314 pounds. He played a key role in a Golden Knights defense that finished first in Conference USA and fourth in the nation by allowing 82.77 yards rushing last season.

Carrington is a pass-rushing specialist, who's listed at 6-foot-5 and 285 pounds. A four-year starter, he finished with 21½ sacks to rank second in school history and fourth on the Sun Belt Conference list. Carrington was also the conference's 2008 defensive player of the year after registering 10½ sacks.

Troup will compete for a job behind projected starter, veteran Kyle Williams. Carrington will compete for a job behind Marcus Stroud and newly acquired free agent Dwan Edwards at defensive end.

The Bills also have a question mark with veteran defensive end Aaron Schobel, who is contemplating retirement this offseason. Nix said Schobel still hasn't made up his mind, and the team is still awaiting his decision.

Though Troup played in a 4-3 system at Central Florida, he's ready to make the switch in Buffalo.

Being selected in the second round came as a surprise for a player projected to be a third-round prospect at best.

"I feel like I was a bit overlooked this year," said Troup, who earned conference second-team honors as a junior and senior. "For the Bills to grab me at the beginning of the second round is a great feeling and that tells me somebody is paying attention to all the hard work I'm putting in."

Troup didn't begin playing football until his first year in high school, and proved to be a quick bloomer. He was a three-time letter-winner at Salem High School in Conyers, Ga., and earned All-State honors as a junior and senior.

As a true freshman, Troup battled weight problems and had only three starts in nine games, before taking over as a full-time starter in his sophomore season. He was credited with 24 tackles for a loss, six sacks and seven pressures in 50 games, including 39 starts.

Troup played under the last name Johnson through 2007 before changing his name to Troup for family reasons.

Carrington's stock rose after he enjoyed a solid week of practice leading up to the Senior Bowl.

"I went in there and did very well against much higher competition than I had at Arkansas State," Carrington said. "I think I opened a lot of people's eyes."

Bills chief scout Tom Modrak was impressed.

"I don't know if it sold you, but Carrington was very good at the Senior Bowl," Modrak said. "It gave you some reassurance."

Barring a trade, the Bills have six picks left over the final four rounds on Saturday, starting with ninth pick of the fourth round (107th overall).

The Bills have numerous needs still to address, including offensive tackle and receiver. Buffalo is coming off a 6-10 season in which it missed the playoffs for a 10th straight year.

Quarterback was perceived to be a big need for the Bills. Nix hasn't ruled out drafting a quarterback, but noted the team is prepared to hold an open competition for the job between Trent Edwards and Ryan Fitzpatrick — who split starts last season — and untested third-stringer Brian Brohm.

Earlier in the day, Bills owner Ralph Wilson dismissed speculation that his team was attempting to trade back into the first round on Thursday to draft Florida quarterback Tim Tebow, who was eventually selected 25th by Denver.

"Denver panicked," Wilson said. "He's a good player, but we had no interest in taking Tebow. We were not moving up to take Tebow."