ESPN College Football

NORMAN, Okla. -- Oklahoma running back Adrian Peterson will skip his senior season and enter the NFL draft.

Woj: Tough call for Peterson
"I bet even today, even after saying it, he still has his reservations because of loyalty reasons: loyalty to his goals and to his teammates," Oklahoma coach Bob Stoops told ESPN.com's Gene Wojciechowski. "I'm all for it. He's been great for us. He's been fun to watch compete. In the end, there's another life for him." • Read more about Adrian Peterson's soul searching.

"In the end, I think I just realized that this is a business decision and that it is time for me to take that next step," Peterson said in a statement released by the university Monday, the deadline for underclassmen to declare themselves eligible for the draft.

"It wasn't easy," he said. "I haven't been sleeping much. I just put it all in God's hands."

Peterson returned from a broken collarbone to run for 77 yards and two touchdowns in Oklahoma's 43-42 overtime loss to Boise State in the Fiesta Bowl. He had been sidelined for seven games with the injury, suffered Oct. 14 on a touchdown run against Iowa State.

Peterson's final carry in an Oklahoma uniform was a 25-yard touchdown run that put the Sooners ahead 42-35 on the opening play of overtime in the Fiesta Bowl.

Peterson opted not to hold a news conference to announce his decision, but said in the statement that he considered his relationships with teammates as a reason to stay at Oklahoma. He said his parents and Stoops were among the people that advised him.

Wesley Hitt/WireImage.comAdrian Peterson ranks third on Oklahoma's career rushing list.

"The last few days have been stressful," Peterson said. "I've been pondering a lot of things and looking at it from all the different angles, weighing the good and the bad."

Peterson ran for 4,045 yards in three seasons, ranking behind only 1978 Heisman winner Billy Sims (4,118) and Hall of Famer Joe Washington (4,071) on Oklahoma's career rushing list. His 1,925 yards in 2004 were a school rushing record and the most by a freshman in NCAA history.

He started that season with an unprecedented nine straight 100-yard games. Peterson also finished second to Matt Leinart in voting for the 2004 Heisman Trophy, the highest showing for a freshman.

Peterson had shoulder surgery in the offseason after his spectacular freshman season, then sprained his ankle and missed parts of four games as a sophomore.

"There were some things that we didn't accomplish," Peterson said. "I didn't really do all of the things I set out to do. Those things, the guys and the love for college football were things I thought about."

He still finished the season with 1,012 yards rushing and 12 touchdowns.

"I know this has been a trying time for him and he just needs to know that we support him wholeheartedly," Stoops said. "Adrian has been a great individual player and a great teammate."

Copyright 2007 by The Associated Press