Sean Mannion is one of the most prolific passers in Pac-12 history.

Sean Mannion is one of the most prolific passers in Pac-12 history.

The 6-foot-5, 220-pound senior already owns 11 Oregon State passing records and is on pace to shatter the conference's career passing mark held by former USC quarterback Matt Barkley.

Despite the impressive statistics — Mannion threw for a Pac-12 single-season record 4,439 yards with 37 touchdowns last season — the Beavers' senior signal-caller still plays in the imposing shadow of his in-state rival.

Oregon's Marcus Mariota is everybody's all-American and a leading Heisman Trophy candidate entering the 2014 season.

The Ducks are picked to win the Pac-12 in the preseason media poll. The Beavers, coming off a 7-6 finish and a bowl victory over Boise State, are projected fourth in the North Division.

"I wouldn't say it motivates me more than I already am," Mannion said of his second-fiddle status to Mariota. "Marcus is a great player obviously. I've gotten to know him and he's a great guy. I want to win games regardless of who's playing in Eugene.

"I think it's good for both schools for both teams to do well, and he's done great things at Oregon."

Mannion, who also put the NFL on hold for a year to take care of some unfinished business in college, threw for 314 yards and two touchdowns at Autzen Stadium last November during a Civil War instant classic.

Oregon State took a 35-30 lead on a Victor Bolden touchdown run with 1:38 remaining, but that provided Mariota with plenty of time to march the Ducks down the field and deliver the game-winning touchdown pass to Josh Huff with 29 ticks left.

At the Pac-12 media day event, Mike Riley pointed to USC's national title runs under Pete Carroll as being important in raising the bar for the conference. The Beavers coach added that Oregon is the one that has responded best to the challenge in recent years.

"Everybody had to step it up or you would get left in the dust football-wise. I mean, (USC) set the standard at the time, and everybody had to rise up," Riley said. "I think our league got better from that. Oregon has done that. They've done that football-wise, they've done that in facilities, so everybody's got to push to do that."

So can the Beavers close the gap in 2014?

Mannion's favorite target, Brandin Cooks, is now catching Drew Brees' passes with the New Orleans Saints. Bolden will play Cooks' position this fall opposite the team's second-leading receiver, Richard Mullaney (788 yards, three touchdowns).

Tight ends Connor Hamlett (364 yards, five touchdowns) and Caleb Smith (343 yards, four touchdowns) are both reliable targets.

"We'll have a much more balanced group. We have a lot of young guys coming off a redshirt and stepping in for their first chance to play. I feel good about how they looked in the spring," Mannion said. "They'll continue to develop and step into a bigger role. We have a very versatile group of tight ends, a very versatile group of backs and one of our strengths is how we use our different personnel.

"I think it will suit us well to get everyone involved and distribute the ball."

Established running backs Terron Ward (521 yards, five touchdowns) and Storm Woods (477 yards, six touchdowns) are hungry for more action. The key to the season will be bringing along an offensive line Riley described as a "mess" in the spring.

Oregon State, which hired John Garrett away from the NFL in February to be the new offensive coordinator, plans to use a more balanced approach this season.

The Beavers led the Pac-12 in passing (372.6 ypg) and were 11th in rushing (94.4 ypg) in 2013.

"I think I actually became a little bit of a victim of it myself early because we were so good throwing the ball for six games," Riley said. "It was pretty incredible. So I think that we probably threw more earlier than I should have to develop that running game into what it could have been because (Mannion) was throwing high 70 percent. His touchdown-to-interception (ratio) was crazy good. His yardage was leading the nation."

Oregon State wasn't much better at stopping the run, yielding 190.3 yards per game. And that was with Scott Crichton (19 tackles for loss, 7 1/2 sacks), who is currently making a strong impression with the Minnesota Vikings during his rookie training camp.

Defensive end Dylan Winn (67 tackles) is the lone returning starter up front, although there are some beefy if unproven tackles — including Siale Hautau (6-1, 350), Noke Tago (6-1, 305) and Jalen Grimble (6-2, 300) — ready for their turns in the rotation.

The Beavers are deep at linebacker with the comeback of Michael Doctor, who was granted a fifth year of eligibility after suffering a season-ending knee injury in the second game last season. The 6-0, 227-pound senior led the team with 83 tackles in 2012.

Doctor (weak side) will rejoin D.J. Alexander (strong side) and Jabral Johnson (middle) as the likely starters, although backups Rommel Mageo, Darrell Songy and Caleb Saulo will push for playing time.

The secondary is also a strength with 2013 leading tackler Tyrequek Zimmerman (104 tackles) and Ryan Murphy (74) back at the safety spots. OSU must replace standout cornerback Rashaad Reynolds, but Stephen Nelson had six interceptions last season.

"I think down the middle of our defense we should be good," Riley said.

The Beavers dropped last year's opener at home to Eastern Washington, which means Riley should have his team focused on taking advantage of the seemingly forgiving nonconference slate of Portland State, Hawaii and San Diego State.

OSU has three difficult Pac-12 road games at USC, Stanford and Washington.

The Civil War, on Nov. 29 in Corvallis, will provide Mannion with one more opportunity to step out of Mariota's shadow as college adversaries.

"It brings our team the utmost confidence having a leader like Sean Mannion," Doctor said. "He's going to take command of the offense and make sure they're on point."