For the first time in years, Oklahoma enters a season with questions on both sides of the ball.
Coach Bob Stoops' expectations, though, haven't changed one bit.
The 16th-ranked Sooners go for a fourth consecutive season-opening victory Saturday night in their first matchup with visiting Louisiana-Monroe.
After going 10-3 and winning a share of the Big 12 title last year, it remains to be seen how Oklahoma will fare after losing star quarterback Landry Jones to the NFL. The Sooners will also likely need to show significant improvement on defense if they hope to contend for a national championship.
"We've got a challenging year ahead of us, and it really starts from the beginning," Stoops said. "We understand and know it's going to be a challenge, but again, I believe it has our players' attention."
The Sooners are counting on big things from Trevor Knight, who is set to replace Jones after beating out junior Blake Bell for the starting quarterback job.
"He's a player," center Gabe Ikard said of the freshman. "He's going to get out there and use his ability. He's got a great arm and he's extremely fast. We're going to get to see and all-around quarterback. He makes good decisions. I know he hasn't played any games yet, but he's a rare talent. It's very exciting to have him behind us and we're very excited what he can do."
The 6-foot-6, 252-pound Bell, meanwhile, still remains a big part of the Sooners' plans. He figures to do most of his damage in short-yardage situations, but could be used in other areas, too.
"We're not going to just detail all of it for Louisiana-Monroe or anyone else," Stoops said of Bell, who ranks third in the conference with 24 rushing touchdowns over the previous two seasons. "I think it's fair to say we'll see as it goes, you know, what we do and don't do with the two of them. I think a lot of it is predicated by what happens once he's on the field."
After surrendering an average of 37.8 points over last season's final five games, Oklahoma is looking to get back to its dominating defensive ways. The Sooners struggled mightily against the run in 2012, yielding an average of 192.2 yards to rank just ahead of Kansas' conference-worst mark of 192.6.
Oklahoma's season ended on an especially sour note after giving up 633 total yards in a one-sided 41-13 loss to then-No. 10 Texas A&M in the Cotton Bowl.
"I feel like I have a lot to prove, since last year was a down year," senior linebacker Corey Nelson said. "It's not even just me; it's just the defense as a whole. We all have something to prove. After last season, especially the last game, we have something to prove."
The Sooners could be in for a stiff test against Louisiana-Monroe, which upset then-No. 8 Arkansas 34-31 in overtime in last year's season opener. The Warhawks averaged 33.8 points in going 8-5 in 2012, losing to Ohio 45-14 in the Independence Bowl.
"With all these starters back, they're a team that is very used to coming into stadiums and places like this and playing well," Stoops said.
Louisiana-Monroe is led by senior quarterback Kolton Browning, who threw a Sun Belt-high 29 touchdowns and finished third with 254.1 passing yards per game.
"Kolton Browning is probably the best offensive player in that league," Stoops said. "I think he's a great player, and he has a lot of experience around him."
Browning, the Sun Belt preseason offensive player of the year, completed 42 of 67 passes for 412 yards and three touchdowns against the Razorbacks last year, adding 69 yards and another score on the ground. The Warhawks had dropped each of their first 23 matchups against ranked foes before beating Arkansas.
The Sooners will have to get by without defensive end D.J. Ward, who had his spleen removed earlier this month. He is expected to miss about six weeks.
Oklahoma will be also missing offensive lineman Jacob Reed. The senior was suspended Monday after he was charged with assaulting his ex-girlfriend and breaking into her apartment over the weekend.