Taiwan Johnson came to Arkansas as a 235-pound defensive end.

Two years later, the redshirt sophomore is a first-team nose guard.

Arkansas coach Bret Bielema said Sunday the 260-pound Johnson has been elevated to the starting unit in place of Demarcus Hodge after the Razorbacks’ first scrimmage. It’s an unlikely spot for Johnson in a conference that typically boasts big men who top the 300-pound mark. But defensive line coach Rory Segrest said Johnson has earned the promotion after one week of preseason camp.

"He’s quick, he’s explosive and he makes plays," Segrest said. "We’re trying to get our best four guys on the field, our best four playmakers. As far as from a productive standpoint, he’s getting out there and doing what we ask him to do."

Johnson said he never imagined playing on the interior of the defensive line when he came to Arkansas in 2012. He moved inside last preseason and it took him some time to adjust, but Johnson appeared in three games as a redshirt freshman.

"It was different. At first, I wouldn’t lie if I said it wasn’t challenging," Johnson said. "And I mean, there’s time where it still is being a smaller guy. But I take that with pride. I’m a smaller guy weight wise, but I have the heart and I have the grit and I’m going to give it all I got to make sure I get my job done for my team."

Johnson said sound technique is key to success at his size. Bielema said it was evident Saturday, when Johnson overpowered guard Denver Kirkland on one play.

Defensive coordinator Robb Smith said his work has been evident since the spring.

"He’s a guy that’s tried to do things the way we ask him to do it," Smith said. "He’s gotten better and improved on a daily basis and really he’s merited it with his performance. At the end of the day, you’ve got to find the best 11 guys to get on the field. We’re going to try shuffling the deck a little bit and see how this mix looks."

In addition to Johnson’s promotion to first-team nose guard, Bielema said the Razorbacks have moved Hodge over to defensive tackle behind returning starter Darius Philon. Freshman Bijhon Jackson — who missed Saturday’s scrimmage with an ankle injury — is working as the second-team nose guard behind Johnson.

So Johnson knows there’s still plenty to prove to earn a starting spot for the season opener against Auburn on Aug. 30.

"All it’s telling me is I have an opportunity and I should take advantage of it," Johnson said of the promotion to the first-team defense. "I should continue to do what I’ve done to get here and do more. Keep working hard, keep taking care of myself and just run to the ball and play as hard as I can every time I get a chance."

Ollison Back to Defense

Johnson’s elevation wasn’t the only significant change for the defensive front

Bielema said junior Grady Ollison, who came to Arkansas as a defensive lineman before being moved to the offense, is returning to his original position. Ollison will work at defensive tackle behind Philon and Hodge.

"Obviously, he was a kid who was recruited here as a defensive linemen and they switched him over to O-line before we were here," Bielema said. "Just with the development of some of our younger guys and new players coming in, we felt like — and Grady just kind of wanted a fresh breath of air — moving him over to the 3 technique and see what he can do there."

Ollison’s move means freshman Brian Wallace has been elevated to second-team right tackle. Wallace is one of four newcomers on the second-team line, joining left guard Cameron Jefferson, center Frank Ragnow and right guard Sebastian Tretola.

"He’s really talented," Pittman said. "He’s got the foot speed. He’s got all those things. Now, he doesn’t know where he’s going some of the time. … The bottom line is, when Grady was moved, that will allow us to amp up Brian’s reps. We think he’s talented enough where he could help this year. So that will amp up his repetitions."

Depth is Key

Arkansas’ backfield was missing two key contributors for most of Saturday’s scrimmage. But running backs coach Joel Thomas said "nobody went into panic mode" without Jonathan Williams (hamstring) and Alex Collins (groin) because the Razorbacks have much-needed depth at the position.

"It’s football. You’re probably not going to feel the same way on Aug. 3 that you’ll feel in November, the last game of the season," Thomas said. "You’re never going to feel top notch. Having three guys, four with Kody (Walker), I can put him in there any time, that’s what you want. You want to build depth at that position."

Bielema said Collins is expected to practice when the Razorbacks return to the field this afternoon. Williams may miss a couple of days after straining his hamstring, but the junior said the injury was nothing severe Sunday.

"It’s good. I just tweaked it a little bit," Williams said. "We have a great training room so I’ll be back in no time."

Extra Points

• Bielema wasn’t shy about his enthusiasm for the team’s first preseason scrimmage Sunday: "I was like a giggly little school girl (Saturday) afternoon," Bielema said. "I was just so excited about what I saw. I heard things at practice I’d never heard for awhile. Like just the intensity of the hits, the collisions, the ball disruption, the breaks on the balls defensively. Offensively, the big plays that were being thrown and caught by the offense. Those things change games."

• Cornerback Tevin Mitchel has been cleared to participate in full-contact work after being limited the first week of camp. Bielema said Mitchel will return to his spot with the first-team defense with cornerback Carroll Washington. "It’s been a long four months going through my rehab and I finally get to get back on the field and work out with the guys and get out of that green jersey and I’m excited."

• Drew Morgan (6 catches, 117 yards and 2 touchdowns) and Keon Hatcher (3 catches, 65 yards) were the top receivers in Saturday’s scrimmage. But both play the "Z" position in Arkansas’ offense. That might not last. "If they can continue to perform the way they’ve been performing it would be a travesty on my part to have one of them sitting on the bench if they can both be on the field at the same time," Arkansas receivers coach Michael Smith said.

• Jefferson has been busy in his first week with the Razorbacks. In addition to challenging Luke Charpentier for the first-team job at left guard, Arkansas also has had Jefferson getting some work at center. That may not be all: "We may float the idea of popping Cameron out and working him a little bit at left tackle as well, to find out what he can do out on the outside perimeter as well," Bielema said.