UNIVERSITY PARK, Pa. -- Evan Royster is one of the big reasons Penn State's offense was able to hit the ground running this season.

This redshirt sophomore tailback has exceeded even his expectations entering a Big Ten Conference game at Wisconsin Saturday night.

"I'm definitely surprised," Royster said.

He ranks 15th in Divisoni I-A and third in the Big Ten in rushing, with 109.83 yards per game. He's averaging 7.8 yards per carry, has churned out four 100-yard games and has scored a team-leading eight rushing touchdowns.

As a team, the sixth-ranked Nittany Lions are eighth in the country and first in the conference in rushing. They are netting 256.7 yards per game behind a veteran offensive line that includes center A.Q. Shipley, guards Stefen Wisniewski and Rich Ohrnberger and tackles Dennis Landolt and Gerald Cadogan.

Royster's backup, redshirt freshman Stephfon Green, has rushed for 368 yards and four touchdowns. The Lions' 21 rushing scores are the second-highest total in Division I-A, trailing only Oregon's 22.

"We've got a great offensive line," Royster said. "They make my job pretty easy. I can't take too much credit for my success. I can't say I'm that good."

Royster, 6 feet 1 and 211 pounds, turned in one of the best games of his career in the Lions' 20-6 win Saturday at Purdue, despite bruising his shoulder.

He tied his career high with 141 yards rushing on 18 carries and scored on a 4-yard run. Royster also set career-highs with four catches and 53 yards and 194 all-purpose yards.

"Evan Royster is the total package," quarterback Daryll Clark said. "When you have a good back there, and he can chop off yards, you don't have to pass as much. I'm not saying we're not capable of that.

"But he gives defenses something else to focus on. He really takes a lot of the pressure off me."

Royster shrugs off talk that he could be a candidate for the Heisman Trophy.

"I think it's a ridiculous thought right now, to be honest with you," he said. "If it happens down the road, that's great. It's not something I'm really concerned about."

Royster had three touchdowns in the opener against Coastal Carolina and three more against Syracuse two weeks later.

He didn't play past the third quarter in any of the first four non-conference games, yet managed 141 yards against Oregon State and 101 against Syracuse. Two weeks ago, in the Big Ten opener against Illinois, he racked up 139.

"To be totally honest with you, yeah, I'm probably a little surprised he's had that much success," coach Joe Paterno said. "But you've got to give not only him, but the offensive line some thought, and the fact that Clark adds another dimension, where they have to be careful. They can't jump in there and go all over [Royster] if Clark pulls the ball out and runs with it."

A year ago, Royster began the season as the No. 3 tailback. But after starter Austin Scott was kicked off the team, Rodney Kinlaw took over and Royster became the backup.

Royster, who chose football over lacrosse despite having offers from perennial college powers Johns Hopkins and Virginia coming out of Westfield High School in Fairfax, Va., rushed for 513 yards, a 6.3 average and five touchdowns last season. He capped the season by scoring the winning touchdown on a 38-yard run in the Lions' 24-17 victory against Texas A&M in the Alamo Bowl.

Royster's quick start has not surprised Shipley, a fifth-year senior co-captain from Moon High School.

"We always preach that we're only going as far as the line will take us," Shipley said. "We have to go out and play well for Evan to play well. Same thing with Daryll. I don't know if they're going to have the success they've had if we don't do our jobs.

"So yeah, we take pride in that. But Evan has done a great job finding little cracks and hitting holes. He's done a heck of a job running the ball."Big Ten leaders