Arkansas coach Bobby Petrino announced Monday that both seniors will be suspended for Friday's season finale against LSU because of a violation of team rules.
Robinson and Mitchell didn't travel to Starkville for last Saturday's 31-28 loss at Mississippi State, and they'll miss their second consecutive game this week.
Petrino didn't elaborate on what team rule the two former starters violated. But a source close to the team said the suspensions stem from an ill-advised practical joke that occurred on the flight home following a 34-21 loss at South Carolina on Nov. 8.
"They were going to be suspended for the last two games," Petrino said. "It was a situation that happened, something with team rules. We talked about it last week (about) whether we should announce it."
Mitchell started the first four games of the season at nose tackle, but he lost the job to freshman Zach Stadther and has recorded only 18 tackles in seven games.
Robinson, who had a breakout year in 2006 with 8 1/2 sacks, has recorded only two this season and has spent all but two games as a backup. He returned a fumble 80 yards for a touchdown in a 52-10 loss at Texas on Sept. 27.
Petrino reaffirmed that redshirt freshman Nathan Dick will remain Arkansas' starting quarterback for the final game of the season.
Dick looked impressive in his first career start, leading the Razorbacks to a pair of quick touchdowns against MSU and nearly pulling off the comeback in the final seconds.
Dick completed 25 of 43 passes for 333 yards with three touchdowns and one interception, leading Petrino to say immediately after the loss that he expects the redshirt freshman to start against LSU.
"I anticipate Nathan starting," Petrino said Monday afternoon. "Something would have to change for him not to."
Petrino said he'd like to find a way for senior Casey Dick — who started the first 10 games before getting benched — to get some playing time in his final game with the Razorbacks.
The plan was for Casey Dick to relieve his younger brother in the second quarter against MSU, but Petrino decided to play Nathan Dick for the entire game.
"I would like to get Casey in the game. I wanted to get him in last week," Petrino said. "... He's back, he's healthy, he's practiced hard and done a nice job preparing for games. If the opportunity comes up, I'd definitely like to get him in the game."
Petrino offered more bad news about his struggling defense, saying that starting middle linebacker Wendel Davis will likely miss Friday's game because of a leg injury.
The junior suffered the injury last Saturday against the Bulldogs, and it was apparent that the Razorbacks weren't as physical once they lost one of their leading tacklers.
"I don't think Wendel will be there (against LSU). It's good news in the fact that there's not a broken bone. All the X-rays were good," Petrino said. "... But I wasn't encouraged after the report (Monday) morning on him being ready for the game."
If Davis can't play, Arkansas will be forced to shuffle its linebackers to make up for the loss.
Redshirt freshman Jerry Franklin will likely move over to middle linebacker since he played the position earlier in the season, and senior Elston Forte will take over as a starting outside linebacker.
"We'll have to look at it and see what combination works best," Petrino said.
Meanwhile, safety Jerico Nelson has a chance to play Friday after being sidelined with a strained knee.
Robinson, Mitchell Will Remain Suspended
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