Safety Elton Ford and cornerback Andru Stewart have lined up with the first-team defense in place of Tramain Thomas and Ramon Broadway, respectively, this week.
Robinson didn't announce they'll start against the Aggies on Wednesday, but said both are competing for positions.
"We've got a couple guys, to be honest with you, that what we're doing is we're splitting time with the first unit and we'll see how they practice this week," Robinson said.
Ford, who started at free safety last season, played last Saturday for the first time since suffering a neck injury against Ole Miss in October 2008. Robinson said he was on the field for more than 30 plays and notched four tackles.
"He did pretty good," Robinson said. "He had some production and he tackled very well."
Stewart has opened the season working on special teams and in a reserve role at cornerback. But Robinson said Stewart's performance on special teams showed he could be physical. He also proved to be assignment sound whenever he lined up at cornerback.
Robinson said Stewart has made progress since spring practice, when he looked "overwhelmed." Stewart believes it's because he's much more comfortable in the defense.
"It was just an adjustment period," Stewart said. "Getting into the playbook, trying to learn a new system, new terminology, things like that. ... It was a progression."
• Starting offensive tackle DeMarcus Love returned to practice Wednesday with a brace on his right knee. Love, who missed Tuesday's practice, was injured in the second half at Alabama but did not miss any plays. Love is expected to start Saturday against Texas A&M.
• Arkansas coach Bobby Petrino said Wednesday he's "not happy" about his offense's performance on third down (8 for 38). However, Petrino hinted at a couple of potential solutions.
"We've got to get back to doing what we're doing," he said. "We haven't been able to get the ball to (tight end) D.J. (Williams), who is a guy who converted a lot of third downs last year. And it will be great to have Lucas Miller back."
Williams has been limited to 8 catches for 104 yards this season. Miller returned to the field last week after missing the first two games with a broken collarbone.
• Texas A&M is sixth in the nation in rushing, averaging 244 yards a game. But coach Mike Sherman isn't impressed.
"I think we should be better than we are," Sherman said. "A lot of those runs are from (quarterback) Jerrod Johnson scrambling and making plays with his legs. I want our tailbacks to carry the brunt of that load. Not to say that if Jerrod has a run not to take it, but I think there's certain aspects of games, particularly in the first quarter, that I think we were slow to get started. That's been a little disheartening."
Arkansas has been reminded of its win against Tulsa last season as it has prepared for Texas A&M. The Aggies offense — a no-huddle, spread attack — is similar to the Golden Hurricane because of how quick it moves from snap to snap.
Texas A&M is averaging 85 plays a game.
"It is a fast pace," Robinson said. "You've got to have that type of pace when you're getting that many plays."
The Aggies lead the nation in total offense (574.3 yards a game) and scoring (45 points). Robinson said Texas A&M doesn't move quite as fast as Tulsa did last season, but the pace will make it challenging for defensive substitutions.
The Razorbacks have rotated players at several positions so far this season. Especially on the defensive line.
"We will rotate guys, but it's hard to substitute on and off at the pace that they give you," Robinson said. "We learned that from Tulsa. I think we got caught two or three times last year, trying to do that during a series. They're not going to wait for you. The ball is marked and ready to go."
Secondary Shake Up?
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