Posted by ESPN.com's Tim Griffin
Here's a look at the Big 12's most pressing early concerns as teams break for the summer for a couple of weeks before returning in June to begin conditioning drills to prepare for the upcoming season:
1. Can Texas find a running game? The Longhorns are still looking for a featured back after no player really emerged during the spring. Cody Johnson had the best early production before he was slowed late in training camp with a hamstring injury. Neither Vondrell McGee or Fozzy Whittaker jumped forward during the spring. Heralded freshman Chris Whaley will get his chance once fall practice begins, but likely won't be counted on early. But filling the hole is important. The Longhorns desperately need somebody as they likely can't challenge for a national championship if Colt McCoy again is their leading rusher.
2. Is Oklahoma's offensive line capable of playing at a level to win conference championships and beyond? After being called out before spring practice for its lack of diligence in conditioning, Oklahoma's offensive line had an uneven spring practice. Four new starters need to emerge along with Trent Williams, who returns and moves to left tackle to protect Sam Bradford's blind side. The unit's growth will determine much of the Sooners' offensive success -- even with the return of talented skill-position players like Bradford, Chris Brown, DeMarco Murray, Jermaine Gresham and Ryan Broyles already in place.
3. Is Oklahoma State's defense really good enough to compete for the Big 12 title? Veteran defensive coordinator Bill Young was counted on to boost production in a unit that didn't seem ready late last year after being blistered for averages of 58.5 points and 593 yards per game in late-season losses to Texas Tech and Oklahoma. The Cowboys have another season of experience and some strong individual players like Perrish Cox and Andre Sexton. But unless they find a pass rush, their hopes of challenging for their first Big 12 South title will be dubious.
4. Can Kansas find linebackers who will enable them to contain Big 12 defenses? The Jayhawks lost three capable playmaking linebackers in James Holt, Mike Rivera and Joe Mortensen from last season. Coach Mark Mangino has hinted that he's considering a 4-2-5 alignment to better combat the Big 12's spread offenses. But he still has to hope that Jake Schermer and Arist Wright prove to be capable replacements -- or it could be a long season for the Jayhawks against their tough schedule of Big 12 South power teams like Oklahoma, Texas and Texas Tech.
5. How much will Texas Tech miss Graham Harrell and Michael Crabtree? Most are thinking that the loss of Harrell and Crabtree will be too much for the Red Raiders to overcome. But Texas Tech coach Mike Leach has quietly -- at least for him -- maintained that he likes his current group of replacements. Taylor Potts will have more experience coming into the program than any of the one-year players who preceded Harrell. All that group (Sonny Cumbie, B.J. Symons and Cody Hodges) did was average nearly 4,943 yards and 38.3 touchdown passes per season in their only season starting, so maybe Leach's comments should be considered. And at wide receiver, the Red Raiders won't have the overall star power of Crabtree, but will still have capable replacements in players like Detron Lewis, Lyle Leong, Edward Britton, Alex Torres, Adrian Reese and Tramain Swindall who should be ready.