KNOXVILLE - There's one open spot on Tennessee's offensive line.
The Volunteers' strongest unit is doing some spring experimentation at all five positions anyway.
Alex Bullard and Marcus Jackson are engaged in an ongoing competition to replace the departed Dallas Thomas at left guard, and with left tackle Antonio "Tiny" Richardson unable to practice this spring as he recovers from offseason surgeries, the coaches are tinkering and cross-training with the offensive front.
"Anywhere they need me, I'm comfortable," Bullard said after Tuesday's morning practice. "That's my job, is to be the swingman in case a certain situation goes down. We have to have more depth, and I'm that guy that can move around right now.
"We're still looking at a lot of different things, but we've just got to keep working."
Earlier this spring, Marques Pair, a fourth-year junior, worked with the first-team line at left tackle. After the first scrimmage last month, Jackson worked at left guard while Bullard filled Richardson's spot. There was more shuffling Tuesday morning, though.
Right guard Zach Fulton played right tackle, where Ja'Wuan James, who shifted over to left tackle, normally plays, while Jackson took Fulton's spot and Bullard slid to left guard.
"This was the first day that happened," said Jackson, the 6-foot-2, 310-pound junior who started five games as a freshman and played left guard in every game last season in the Vols' seven-man rotation. "It was kind of a surprise, but at the same time I thought it was a challenge and went out there and tried to do what I could."
Though the expected lineup in preseason camp will be, from left to right, Richardson, Jackson or Bullard, center James Stone, Fulton and James, the versatility helps both the team and the individual linemen.
"When it comes to the next level, people being able to play many positions helps," Bullard said. "Zach, he plays center and tackle, and that'll help his draft stock. Ja'Wuan can play both right and left tackle, and that'll help his draft stock.
"We're just looking at a lot of different things. Today we came back strong and had a better day. We've just got to keep plugging along."
Bullard, a 6-foot-2, 300-pounder from Nashville who transferred to Tennessee from Notre Dame two years ago, has started games at guard and center and lined up as a tight end in the Vols' jumbo packages last season.
"Alex has done a great job," new head coach Butch Jones said. "Alex is one of those individuals who just comes to work every day. He doesn't care where he plays, he loves football and he continues to get better and better and progress.
"Competition is healthy, and I think they're pushing each other. We're developing depth now, and we're developing No. 6. I think that's important, so that's why competition across the board is extremely healthy for your entire football team."