"I'm up to 264 pounds now," he said. "I was about 255 last fall."
Although he's still smaller than many SEC defensive ends, Walls readily concedes that the nine pounds he added in recent months is enabling him to better hold his ground in the trenches.
"That helps, but I've got a long way to go," he said. "I'd like to get up to 275 or 280. I'm working with the nutrition ladies every day, trying to keep putting that weight on."
Because he routinely faces offensive guards who outweigh him by 30 to 50 pounds, Walls has learned that technique and agility are his keys to survival.
"I have to rely on quickness," he said. "I can't let those big guys lock up on me. It's pretty much over then. You have to rely on technique and quickness. That's pretty much my game plan."
This "game plan" worked well enough to enable him to letter as a freshman last fall. He saw backup action in seven games and recorded 2 solo stops. Now that 2009 starters Dan Williams and Wes Brown are gone, Walls and fellow sophomore Montori Hughes are the projected starters at defensive tackle. Both understand that they have big shoes to fill.
"Replacing Dan Williams and Wes Brown is very hard to do," Walls said. "I don't think we'll be able to replace them but I think we can bring something new in. We've got a lot more work to do but we're looking at filling them spots and helping our defense out."
At 6-3 and 264 pounds, Walls is dwarfed by the 6-4, 317-pound Hughes. The two sophomores are a lot closer in their bond than they are in their body types, however.
"He's like my right-hand man," Walls said of Hughes. "We know we're going to have to depend on each other so much, and both of us have a lot of growing up to do. We're super tight right now. It's going to be up to us to get the job done, so our bond is about to get a lot stronger. We've got to rely on each other a lot more, so that's where we are right now."
Because he lacks ideal heft, Walls struggles with double-team blocks. He's working hard to develop the leverage necessary to improve in this area.
"It's all about keeping a flat back and being confident in taking on double-teams," he said. "Coach (Chuck) Smith is a good D-line coach, and he instilled in me that the double-team is not as tough as it seems, as long as you keep your back flat and shoot them hands. You've got to be able to control the guard."
With two sophomores starting at tackle, Tennessee is fortunate to have three seniors at end - Chris Walker, Ben Martin and Gerald Williams. Walker started 12 games last fall, Martin 11 and Williams 2. Their experience on the outside should help cover for Hughes' and Walls' inexperience on the inside.
"It helps a lot because we know we can depend on those guys," Walls said. "We know they're going to do their jobs and they're going to make sure we're doing ours. It's a pretty good boost to look out there and see you've got some experience on the outside."
Even with depth seriously lacking at tackle, Tennessee's first-team defensive line appears to be reasonably solid.
"We're pretty good," Walls said. "We've connected. We've got all kinds of hand signals and handshakes, so we've bonded a lot. We spend a lot of time together, just kicking it.
"We know in order for us to get it done it's going to take energy and togetherness. We look forward to depending on each other a whole lot."