EUGENE — Fall football practice finally began Monday for Oregon, though the question the Ducks have been attempting to answer since 2007 Heisman trophy frontrunner Dennis Dixon went down with a knee injury last November remains the same.

Who, exactly, will be the starting quarterback for Oregon when they open the season at Autzen Stadium against Pac-10 Conference rival Washington on Aug. 30?

“There’s a void there,” admitted Mike Bellotti, who is beginning his 14th season as the Ducks coach. “(Dixon) became one of the greatest players to ever put on a uniform (here) and last season he was one of the most dominant players in college football. Having said that, I’m fairly comfortable and confident with our quarterback position.”

At the moment, it appears Nate Costa has the upper hand. The 6-foot-1, 215-pound redshirt sophomore has mobility like Dixon, but with a stronger arm.

Costa had reconstructive knee surgery last fall after tearing his anterior cruciate ligament during an October practice. That injury was credited for the Ducks’ late-season downward spiral as much as the knee injury that ended Dixon’s senior season with four games to play.

But after competing just lightly during the spring, Costa has emerged through summer workouts and looked sharp on Monday.

“I’m in a great place right now,” Costa said. “I feel like I’m 100 percent. My speed numbers are back up, my strength numbers are back up and I felt good out there today.”

For all of Costa’s potential, he has still only appeared in two games in his Oregon career — both in 2006 — going 5-for-5 for 73 yards in mop-up duty.

“I’ve been very pleased with what Nate accomplished when he played before,” Bellotti said. “He brings leadership, toughness and he is totally healthy.”

But it was 6-6 sophomore Justin Roper who moved from fifth string backup to Sun Bowl starter last season, throwing for 180 yards and four touchdowns in Oregon’s 56-21 postseason win against South Florida.

“Justin Roper is going to have a say in this thing,” Bellotti said.

As could a pair of heralded true freshmen in Chris Harper and Darron Thomas, as well as sophomore transfer Jeremiah Masoli, who led City College of San Francisco to the junior college national championship last season while throwing for 3,592 and 30 touchdowns.

“We probably won’t name a starter until late in camp,” Bellotti said. “Until we say, ‘Yes, this guy is it,” quarterback is a question mark.”

The Ducks also lost running back Jonathan Stewart, who left for the NFL after a junior season that saw him set a school record with 1,722 yards.

However, they return senior Jeremiah Johnson, who as Stewart’s backup the past three seasons accumulated 1,135 yards and 17 touchdowns, and added 6-2, 229-pound junior LeGarrette Blount, the top-rated junior college running back in the nation last season who is as big as any of the Ducks starting linebackers.

“LeGarrette Blount had a tremendous offseason,” Bellotti said. “He had maybe one of the best summers that we’ve had from anybody on our football team in terms of work and progress.”

Add to that the return of an experienced offensive line, conference sack leader Nick Reed, a defensive backfield with three potential all-Americans in safety Patrick Chung and cornerbacks Jairus Byrd and Walter Thurmond III, and Oregon opens with optimistic expectations.

“I really like the character and the chemistry and the confidence of this football team,” Bellotti said. “I think there’s great leadership across the board on both sides of the football ... They are as excited to start practices as anytime in my memory of my 20 seasons here.”