Austin, Texas ? The Texas Longhorns revealed their first depth chart for the season with a few new faces and a bit of anxiety about their pass defense.

Freshmen Earl Thomas and Blake Gideon are listed as the top safeties for today’s season opener against Florida Atlantic.

And backing them up? Three more freshmen, meaning there won’t be a down of experience up the middle of the field in a secondary that ranked 109th nationally against the pass in 2007 and gave up school records in yards and touchdowns.

The No. 11 Longhorns announced that the one safety with any experience, junior Ishie Oduegwu, is out indefinitely after shoulder surgery. Oduegwu had played in 25 career games with three starts.

“It’s a real concern,” coach Mack Brown said. “(But) they are very talented.”

Given the secondary’s recruiting pedigree, physical talent shouldn’t be a concern. Maturity and experience will be.

Thomas has been a standout in training camp, and backups Ben Wells, Nolan Brewster and Christian Scott all were high school all-Americans. But high school will seem like ancient history when Texas hits the meat of its Big 12 schedule against some of the best quarterbacks and most high-powered offenses in the country.

Brown says it reminds him of a talented but young secondary a few years ago that included Michael Huff, Cedric Griffin and Michael Griffin. Those three are now all playing in the NFL.

“We had some growing pains (then) and we’re going to need some help (now),” Brown said.

After last season’s struggles, Brown hired new defensive coordinator Will Muschamp away from Auburn in the offseason and made him one of the highest-paid assistants at $425,000 a year.

The Longhorns have had to simplify some of the defensive calls to help their young players feel comfortable on the field.

They’ve dropped terms such as “strong” and “free” safety and assigned positions as “left” and “right” to limit their defensive calls and give the new starters areas of the field to cover.

“The calls are simpler,” Brown said. “We can simplify what they do back there much easier.”

The Longhorns don’t seem to have settled on a tailback, which has been one of the most intriguing battles of training camp. Texas probably will use both sophomore Vondrell McGee and senior Chris Ogbannaya.

A strict reading of the chart would show McGee as No. 1, but right behind his name is the word ‘or’ meaning Ogbannaya could just as easily get the first carry against Florida Atlantic.

Freshman Fozzy Whittaker had been in the mix but lost ground after a minor knee injury in practice.

The Longhorns have been searching for a starter since last January when Jamaal Charles, who rushed for more than 1,600 yards last season, announced he was leaving for the NFL a year early.

“We’ll play both,” Brown said. “The one that runs out there first it really doesn’t matter.”