Quick, name the most devastating injury that occurred in last season’s Georgia-Tennessee game.

Tennessee coach Butch Jones would understand if you pointed toward Georgia running back Nick Chubb's brutal season-ending knee injury from that game -- Chubb is one of the nation’s best running backs, after all -- but Jones lost a crucial player of his own that day.

Volunteers defensive lineman Shy Tuttle was starting to establish himself as a true freshman when he broke his leg and tore an ankle ligament following a low block by Bulldogs offensive lineman Brandon Kublanow. The injury forced Tuttle to miss the remainder of the 2015 season and spring practice -- and even now Jones is unable to set a timetable for when Tuttle will return to full strength.

Shy Tuttle was showing flashes as a true freshman in 2015 before suffering season-ending leg and ankle injuries against Georgia. Charles Mitchell/Icon Sportswire

“He’s progressing. He’s running. He’s been working out,” Jones said last week during his SEC Car Wash appearance at ESPN headquarters. “He’ll be very limited in training camp. And so we’ll know a little bit more probably mid-August of where he’s at. He’s done a great job of rehabbing his injury, but it was one of those devastating injuries that takes a lot of perseverance to come back from.”

Tuttle generated major buzz last August and was beginning to prove why ESPN’s recruiting analysts rated him as the nation’s No. 41 overall prospect when he signed with the Volunteers last year. In a narrow loss to Arkansas the week before the Georgia game, Tuttle recorded a season-high five tackles and blocked a 22-yard field goal that kept the Vols within striking distance late in the third quarter.

A week later, his season was done.

Once Tuttle returns to the lineup, Jones is optimistic that he can help transform a relatively shallow interior line. Veterans Danny O’Brien and Kendal Vickers both have starting experience, but sophomores Tuttle and Kahlil McKenzie -- ESPN’s No. 26 overall prospect last year -- are the greatest sources of optimism among Vols fans.

Because of his size and athleticism, Tuttle’s return will be valuable in multiple ways for the Vols.

“It makes us much better,” Jones said. “Shy has the ability to win a one-on-one matchup as a 3-technique. He can run, he’s very athletic, he’s physical, he’s tough. Prior to his injury, as a true freshman, he was playing as well as anyone we had on defense. So we need to be able to generate an interior pass rush. That’s going to be critical for us.”

Tuttle is part of a big group of Tennessee defensive linemen who missed all or part of spring practice -- a group that also included All-SEC defensive end Derek Barnett, Vickers, defensive end Corey Vereen and promising defensive end Kyle Phillips.

Those absences exposed one of the leading questions for Tennessee as it enters the 2016 season as an SEC East favorite: Do the Vols have enough defensive line depth to withstand injuries to key players?

Without question, Tuttle’s return will help in that regard, but Jones acknowledges that his team still must fill its holes up front if Tennessee is to enjoy long-term success on his watch.

“It all starts up front, in our front seven, in our ability to impact the quarterback,” Jones said. “When you talk about how it takes years to build a program, not just a team, that’s still where we’re at in the development phase of our football program. We still need to grow and develop our front seven.

“For us, it’s going to be who’s the fifth defensive lineman in the rotation. Who’s No. 6? We still haven’t identified who our No. 3 linebacker’s going to be. So to me, it’s the constant depth at a number of positions.”