BATON ROUGE, La. -- The LSU Tigers lost one the few veterans on its interior defensive line in the first week of preseason camp when Quentin Thomas tore a bicep on Wednesday.

LSU sports information director Michael Bonnette confirmed that Thomas had suffered an injury after the fourth-year junior missed practice on Thursday and Friday, but the Baton Rouge Advocate reported that he is expected to miss the season.

"With him going down, he's a great friend of mine [and] I felt terrible when I heard about it," sophomore defensive tackle Christian LaCouture said after Friday morning's practice. "Somebody's got to step up."

LaCouture and Thomas were listed as starting tackles on LSU's preseason depth chart, although they have only one start between them. Thomas started in place of Ego Ferguson in last season's Outback Bowl when Ferguson did not play in the game. He finished last season with nine tackles in 11 games.

Thomas redshirted in 2011 and contributed in a minimal role in 2012. He finally saw the field a bit last season and said earlier this week that he was excited to have a chance to truly make an impact.

"Redshirting and not playing as much for the past few years has helped me learn my plays and put me in a better position for when they do give me my chance, I'll be able to perform well," Thomas said after Monday's first preseason practice.

Now it looks like it will be a while before Thomas gets that chance, which his coach at Breaux Bridge (La.) High School, Paul Broussard, admitted would be a major disappointment for his former player.

"He had worked hard, waited his turn and bided his time and finally had his chance to start," said Broussard, who had not yet spoken to Thomas a couple of hours after the news broke Friday. "I know it has to be devastating for him."

The Tigers now must lean more heavily on a trio of defensive tackles: Frank Herron (LSU coach Les Miles described as "a beast" earlier this week), Greg Gilmore and Maquedius Bain . All three redshirted last season after arriving at LSU as ESPN 300 honorees in 2013.

Additionally, LSU might get some good news about 2014 signee Travonte Valentine soon. Champagnat Catholic (Fla.) coach Mike Tunsil told TigerSportsDigest.com that he expects the NCAA Clearinghouse to permit Valentine to enroll at LSU next Tuesday. Valentine was ESPN's No. 164 overall prospect in the 2014 class and the No. 11 defensive tackle.

Regardless of whether Valentine contributes this fall, the interior line will still feature mostly inexperienced players. The next several weeks of practice will help determine which players figure heavily into defensive line coach Brick Haley's plans.

"Even though I'm a sophomore, I'm trying to be an upperclassman and trying to help with the young guys. A lot of them have to play," LaCouture said. "With everything going on, we're just trying to figure out who's ready to play. I thought we had a great day today."

Thompson playing it smart: Safety Corey Thompson said his surgically repaired knee is completely healthy, but he's still trying to be smart in his return to the field.

"I took limited reps today, but the first few practices, I got them all, I got it in," Thompson said after Friday's first practice in full pads. "So just trying to get back in shape is my main thing."

Thompson missed spring practice following surgery to repair the ACL he tore last season against Texas A&M. He's in the mix to return to the starting lineup this fall -- he had started five of the last six games last season when he went down against the Aggies -- although LSU lists him behind Rickey Jefferson on the preseason depth chart.

Thompson said he expects all of the returning veterans -- a group that also includes Jalen Mills and Ronald Martin -- to contribute this season, as could freshmen Jamal Adams, John Battle and Devin Voorhies.

"We're just trying to teach the freshmen, make sure they understand, because they're going to get some play, too," Thompson said. "So we know that everybody's going to play, everybody's good enough to play, so we're all rotating."

Absences and graduations: Center Elliott Porter was among the Tigers who were absent from Friday's practice periods that were open to the media. The senior sport administration major participated in summer commencement exercises Friday morning at LSU's Pete Maravich Assembly Center.

Porter was one of three current players -- along with fullback Connor Neighbors and Justin Maclin -- to graduate Friday, as did former Tigers Rob Bolden, Richard Murphy and Karnell Hatcher.

Among the other Tigers who were not present during Friday's practice periods that were open to the media: receiver Malachi Dupre, linebacker Clifton Garrett and cornerback Rashard Robinson.