Petrino said Petrus, who started in 2007, will redshirt the season because of an undisclosed issue.
The school won't reveal the exact reason for Petrus' absence, but all signs have pointed to an academic issue. Arkansas said Petrus hasn't committed an NCAA violation and wasn't suspended for disciplinary reasons. He also hasn't sustained a significant injury.
Either way, Petrino said Petrus' absence will hurt Arkansas' depth.
"It thins us out," Petrino said. "It doesn't give us as much depth as we want. We're fortunate that (sophomore) Wade Grayson has been doing a real nice job (as a starter), and we worked him in there all camp and he's done a nice job handling it."
Grayson has worked with the first-team offense for most of the preseason but was expected to battle Petrus for the position all season. Without Petrus, Petrino said junior Michael Aguirre has been working as Arkansas' backup at weak tackle and weak guard.
In addition, Petrino said the Razorbacks are also counting on redshirt freshman Seth Oxner to help at guard, too.
The Razorbacks are planning to welcome linebacker Elston Forte back to the field Saturday.
The senior — who was elected a team captain — has missed two games because of a knee injury. But Petrino said Forte is finally scheduled for contact work in practice this week.
"Hopefully (Forte's return) will be a stabilizing factor," Petrino said. "But again you've got to see how the week of practice goes. Sometimes when you come back that first week and coming off the injury he does, we have to see how he handles the work load.
"How does it swell? Is there soreness? So you don't want to jump the gun, but we anticipate that he'll be back."
In addition, receiver Marques Wade and linebacker Freddy Burton will be in uniform. The two were suspended for two games after offseason arrests. Petrino said they'll help on special teams.
"Both of them are the size and speed that can really contribute in those areas," Petrino said.
Petrino said running back Michael Smith showed plenty of physical and mental toughness en route to 190 all-purpose yards against the Warhawks. But the workload (26 touches) was a concern. The junior needed an IV at halftime because of cramps.
So Petrino said the Hogs must find a way to lighten his load.
"We've got to be able to rotate De'Anthony (Curtis) in there or Dennis (Johnson) in there or Brandon (Barnett) and make sure we can keep him a little fresher in the first half," Petrino said.
Smith — who ran for 121 of his 157 yards in the first half — believes he'll be fine Saturday. The 5-foot-7 running back said his legs cramped up largely because he didn't practice much after learning he wouldn't play in the opener two weeks ago.
"I played a lot of plays," Smith said. "More than I'm used to. I haven't done that since high school."
Adams Earns Honor
Receiver Joe Adams was named Southeastern Conference Freshman of the Week on Monday.
Adams started and caught seven passes for 89 yards in the 28-27 win against ULM. Adams is tied for second in the SEC in receptions a game (five) and is ninth in receiving yards (60.5).
"One thing that Joe is gifted with is very good hands," Petrino said. "He just has to get used to running his routes full speed every time, even when he's not number one in the progression.
"He's got a chance to be a great player for us. Certainly he had a very nice game for us and was a big part of the win."
Who's the Kicker?
Petrino didn't shed much light on Arkansas' place-kicking situation during Monday's press conference.
He was asked if Alex Tejada, who missed two field goals and an extra point, and Shay Haddock, who replaced the sophomore in the second half, would be competing for the starting job.
"We're just going to work at it one day at a time and try to get better in all phases," Petrino said. "The protection, the snap, the hold and obviously the kick."
The Arkansas-Alabama game on Sept. 20 will be televised by Raycom Sports and has been scheduled for an 11:30 a.m. kickoff.
It will be the second game televised this season. In addition, Saturday's Arkansas-Texas game will be broadcast by ABC Sports.
Petrus to Redshirt
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