Oregon State’s Sean Mannion will offer real test for USC’s secondary

Fresno State utilized its game against USC as a quarterback tryout, Stanford played mostly conservative and Boston College attempted only 14 passes.

So Trojans defensive backs are looking forward to Saturday night’s game against Oregon State in what will be their first real challenge from an NFL-caliber quarterback.

Sean Mannion last week became Oregon State’s career passing-yardage leader.

“It’s one of those games you want to be in,” Trojans cornerback Chris Hawkins said. “You want to stay busy during the game.”

Mannion, who has led Oregon State to a 3-0 start, is expected to keep the Trojans secondary hopping.

The 6-foot-5, 227-pound senior from Pleasanton, Calif., has passed for 903 yards and four touchdowns this season, 11,339 yards and 76 touchdowns in his career. Mannion needs 989 yards passing to break the Pac-12 career record of 12,327 held by USC’s Matt Barkley.

“It will be a great test,” Trojans Coach Steve Sarkisian said of facing Mannion.

With senior Josh Shaw suspended indefinitely, Hawkins, a redshirt freshman, has started opposite junior cornerback Kevon Seymour. Sophomore Su’a Cravens and senior Gerald Bowman start at safety.

Freshman Adoree’ Jackson also has played extensively at cornerback and sophomore Leon McQuay III rotates in at safety.

USC is ranked 19th nationally and third in the Pac-12 Conference in passing defense, giving up 166.3 yards a game. The Trojans have not surrendered a touchdown pass.

Defensive backs have three of the Trojans’ five interceptions.

“They’ve played fine,” defensive backs coach Keith Heyward said, “but still not good enough.”

In USC’s 31-14 victory over Oregon State last season, Mannion completed 26 of 45 passes for 277 yards and a touchdown. But USC intercepted three passes.

“They’re great athletes and they cover a lot of ground,” Mannion said in a telephone interview, adding, “you have to be mentally very sharp.”

This season, Mannion passed for 328 yards and a touchdown against Portland State, 300 yards and three touchdowns against Hawaii.

Last week, he passed for 275 yards in a 28-7 nonconference victory over San Diego State.

Mannion said he has improved since last season.

“I really wanted to be accurate and play fast and improve my footwork — and I think I’ve made strides,” said Mannion, who has had two passes intercepted. “In the first three games, I completed passes on time, my footwork was quicker and there was not a lot of wasted movement in the pocket.”

Oregon State — and Mannion — lost a huge weapon after last season when receiver Brandin Cooks made himself available for the NFL draft. Cooks was selected 20th overall by the New Orleans Saints.

Sophomore Victor Bolden, who played at Rancho Cucamonga Los Osos High, stepped into Cooks’ spot and caught a team-best 18 passes before he suffered a finger injury against San Diego State that will sideline him against the Trojans.

Beavers Coach Mike Riley hopes to blend the running of Terron Ward and Storm Woods with Mannion’s passing to a receiving corps that includes former Thousand Oaks High standout Richard Mullaney, Hunter Jarmon and tight ends Connor Hamlett and Caleb Smith.

“It’s unfortunate about Victor but we’re ready for that,” Mannion said.

Sarkisian said the Beavers were adept at “really forcing your secondary to communicate on the fly.”

USC hopes to help its defensive backs by pressuring Mannion, who has been sacked eight times.

“He gets hit but he stands in and delivers the ball down the field,” Sarkisian said. “He’s just a nice mesh with Coach Riley and what they try to do, and they’ve been a good tandem for a few years.”

Follow Gary Klein on Twitter @latimesklein