Here is OU beat writer Ryan Aber's ranking of the Sooners' position groups:
1. Offensive line
Gabe Ikard is a preseason All-American at center and could move over if needed after Ty Darlington showed well in two starts there last season. Bronson Irwin, Adam Shead, Tyrus Thompson and Daryl Williams make for a solid group, and junior college additions Dionte Savage and Tony Feo could push for playing time.
2. Offensive backfield
Make this just about running backs and the unit would probably be No. 1. Damien Williams, Brennan Clay and Roy Finch have all shown potential to be No. 1 guys while Trey Millard at fullback/running back/tight end is one of the most valuable pieces of the Sooners' offense. But the unknown at quarterback — Blake Bell or Trevor Knight — knock this unit down a spot.
3. Wide receivers
The loss of Kenny Stills and Justin Brown will be felt, but the unit is still solid, especially with Jalen Saunders and Sterling Shepard. Big things were expected last season from Trey Metoyer and the extra year in the system could do him as much good as anyone entering 2013.
Could've been a spot lower but it's hard to judge the linebackers on what they did a year ago after the position virtually disappeared as the Sooners struggled to contain the league's most wide-open offenses. Corey Nelson has been one of the talks at camp for his improvement and Frank Shannon was solid last season, especially early.
5. Defensive backs
It's hard to argue there isn't talent there, with newcomers Hatari Byrd, Ahmad Thomas and others looking like they'll be significant contributors in the future, but that talent is largely unproven outside of cornerback Aaron Colvin.
6. Defensive line
The only returning starter — Chuka Ndulue — moves from defensive end inside to tackle. The unit did get a boost with the addition this week of junior college signee Quincy Russell, but there is still plenty of question marks for the group that struggled to get pressure last season.