KNOXVILLE - One new defense and two injuries have given Greg Clark an opportunity.

Now he's just trying to make the best of it.

The Tennessee nose tackle has played in just one game in two years on campus, but with Daniel Hood (shoulder) and Maurice Couch (concussion) sidelined, Clark is taking advantage and receiving some repetitions with the first-team defense.

"Greg's had a good spring," coach Derek Dooley said after Tuesday morning's practice, the Volunteers' eighth of 2012. "Greg was a guy who really nobody talked about until this spring. I think the move to the 3-4 [defense] really gave him a chance because he's a big, thick body. He can hold the point in there and he's playing good for us."

The 6-foot-2, 315-pound rising sophomore played in just one game last season after a redshirt year in 2010. He was a late addition to Dooley's first recruiting class at UT. He signed with the Vols out of Northside High School in Warner Robins, Ga., in April almost two months after signing day.

Clark said he's dropped 15 pounds since last season, which has helped him move better. Hood has been very limited this spring after offseason shoulder surgery, and Couch got hurt last week. Daniel McCullers, the Vols' 6-foot-6, 380-pound nose tackle signee, won't arrive until the summer.

That's left Clark, who admitted UT's new defense is much more suited to his style.

"You've got to be mean," he said. "That's the main thing. You can't be afraid to take on double teams and blocks. You've just got to go out there and play."

Bray watch

In recapping Friday's scrimmage, Dooley noted the team's improvements in running the ball and playing aggressively and tough on defense, but he acknowledged that the Vols struggled throwing the football.

"That starts with the quarterback," the coach said. "Tyler [Bray] didn't play as well as he's capable of playing."

The rising junior completed just 13 of 32 passes for 142 yards, one touchdown and one interception. Dooley attributed some of that struggles to the receivers' inability to break press coverage from defensive backs at the line of scrimmage. But he expressed disappointment in Bray's performance.

"He's having a good spring," Dooley said. "He just wasn't as accurate [and] he wasn't as sharp as he's capable of being. I don't think it was anything that we start panicking over.

"He just didn't throw as well as he can, and not having [receiver] Justin [Hunter] some times hurt. We have a lot of guys out there at receiver probably trying to do too much. I'm not that concerned about it because he's working really hard to get better."

'Sam' scenarios

Brent Brewer's physical limitations coming off an ACL injury forced him to move from strongside linebacker to safety this spring. That's left the door open at the position, which is also called the "Sam" linebacker spot. Dooley ran through some of the guys in the mix there Tuesday:

Raiques Crump has gotten most of the first-team reps. Dooley said the rising junior special-teams ace is "having a really good spring."

Another is rising junior Dontavis Sapp, who played in all 12 games at outside linebacker last season.

Dooley suggested Curt Maggitt, who has been playing one of the inside linebacker spots, as a possibility "depending on where Herman [Lathers] plays." The Vols are trying to see how much Lathers can do nearly nine months removed from a severely fractured ankle.

Rising fifth-year senior Willie Bohannon, who has been splitting time with Jacques Smith at Jack linebacker, the other outside spot, also is a candidate.

So is rising sophomore Jordan Williams, who's mostly played defensive end before working with the outside linebackers Tuesday.

Dooley said the position is still a work in progress.

"We've got bodies," he continued. "It's just finding the right ones."

Fulton returns

Zach Fulton practiced for the first time Tuesday after missing the first two weeks of spring drills recovering from a stress fracture in his foot. The rising junior has started 15 games in a row at right guard, but he'll have to earn his spot back from James Stone, who's been his replacement there this spring. After playing last season at 330 pounds, the Illinois native said he's down to 317.

Fulton said he suffered the injury that put him on crutches and in a walking boot during a conditioning workout nearly six weeks ago.

"We were running six 300s that day, and it was on the last 300," he recalled. "I just heard a pop in my leg. It was the last one -- the last 50 yards, really.

"Big men aren't really meant to run a thousand yards every day, but it is what it is. We make that known all the time."

Status updates

The Vols have switched reserve tailback Jaron Toney to nickelback. ... Safety Geraldo Orta practiced in a red noncontact jersey. ... Freshman running back Alden Hill (undisclosed) did not practice Tuesday. ... Freshman tight end Justin Meredith (hamstring) continues to run on the side at practice. ... Linebacker Christian Harris likely will have surgery to repair a torn ACL in his knee Friday. The redshirt freshman was injured last week.