KNOXVILLE - That's not a walk-on running routes in a number-less jersey with the University of Tennessee football team this spring.

It's a former five-star tight end prospect who doesn't feel like he's earned the No. 1 prestige as a wide receiver yet.

Former Knoxville-area high school star Brandon Warren looks like a blank, orange Scrabble piece after asking coaches for a plain jersey until he performed at his newer position.

Warren, who has always struggled to simply approach typical tight end size, said narrowing his 6-foot-2 frame to 218 pounds was much easier.

"I almost feel like me again," he quipped.

A Florida State transfer who never quite fit in UT's offense last season - despite clearly being one of the team's best playmakers on the practice field - Warren said he asked for a position change shortly after Lane Kiffin replaced longtime Volunteers head coach Phillip Fulmer.

"I was looking toward my future and stuff like that," Warren said. "I can play tight end, but I felt like I could be a better wide receiver in this offense."

Kiffin, who coordinated several successful Southern California offenses that featured big wide receivers, has allowed several UT players to try new positions this spring. Sophomore Cody Pope has removed part-time tight end duties from his plate, focusing exclusively on the offensive line. Junior-to-be Gerald Williams has at least temporarily shifted to linebacker, and redshirted freshman Rod Wilks has moved back to safety after practicing with the wide receivers, safeties and strongside linebackers last season. Some defensive lineman might be asked to help a depleted offensive line, as well.

"We just want our best players on the field," Kiffin said. "If we need to move some guys around and try different combinations, we'll do that. We'll do whatever it takes to be the best we can be on offense, defense and special teams."

Warren - also a defensive star in high school who hasn't ruled out helping that side of the ball at UT - said comfort isn't one his obstacles at wide receiver. He split out wide in some packages at Alcoa High School and Florida State.

"It's still an adjustment, and I've still got plenty of things to work on, but I feel like I'm getting better and better every day," Warren said. "I'm just going to keep grinding and grinding until I get there."

And until he gets there, he won't wear the No. 1 jersey he's worn "forever." Kiffin and receivers coach Frank Wilson didn't object to Warren's self-motivation tactic.

"I need to get my 'swag' back," Warren said. "I'm going with the blank jersey until I feel like I'm back to No. 1. There's just some things I need to work on, and when I work them out and feel comfortable, Coach (Kiffin) said he'll make sure I get my number back."

All-Southeastern Conference linebacker Rico McCoy said Warren is a rare athlete who could play "just about anywhere on the field."

Junior-to-be Gerald Jones, the team's leading returning pass-catcher, said he welcomed Warren into the wide receiver corps.

"He's a big receiver who can move, and he's shifty, and we can use him in a lot of ways," Jones said. "He runs pretty good routes, and we can use him a lot in the red zone with the fade ball. He's going to be a big part of this offense."

That's what Warren had in mind when asking for a position change.

"The offense is designed to get playmakers the ball, and there's going to be all kinds of opportunities out there," Warren said. "We've just got to take advantage of it and be ready to go.

"I'm going to work on my speed and try to get my 40 (yard dash) time down a little bit, and work on my chemistry with the quarterbacks ... and then hopefully I'll be good to go."