CORVALLIS, Ore. (AP) — The difference in Sean Mannion is marked: The once soft-spoken and reserved quarterback for Oregon State has blossomed into a confident full-fledged leader in his senior season for the Beavers.

A perfect fit in Oregon State's pro-style offense, Mannion set a Pac-12 season record for passing yards last season with 4,662. He threw an Oregon State-record 37 touchdown passes, third-most for a single season in conference history.

Mannion, who has 10,436 career passing yards, needs 1,839 more this season to pass USC's Matt Barkley as the all-time Pac-12 leader.

Mannion could have gone to the NFL this spring, but decided to play out his college career.

The Beavers open the season at home Saturday against Portland State.