Tennessee has become a trendy pick to win the SEC East.

The Vols have a lot going for them as a program in coach Butch Jones’ third season, including back-to-back stellar recruiting classes, a rocket scientist for a quarterback, one of the deepest groups of receivers in the country and one of the finest collections of pass rushers in the SEC.

RELATED: Butch Jones advises Vols fans to keep being patient

But as talented as UT is becoming at certain positions, certain spots are thin, and others are full of still-developing youth.

If the Vols stay healthy all season, the team very well could challenge Georgia and Missouri for the SEC East title. But it’s going to take at least one more good recruiting class for UT to be able to compete with the best programs in the nation in terms of the two- and three-deep depth charts.

With that in mind, let’s examine the five players that Tennessee can’t afford to suffer serious injuries in 2015.

5. DE Derek Barnett

The teams have other options here — Curt Maggitt is a threat to reach double-digit sacks, while Corey Vereen, LaTroy Lewis and Kyle Phillips add depth.

But Barnett is a singular talent, the kind of game-changer that can’t be replaced without consequences. Texas A&M’s Myles Garrett may have broken the SEC freshman sack record last season, but Barnett made 10 sacks and 20.5 tackles for loss. He’s a better all-around player than the Aggies standout at this point. A remarkable 18 of Barnett’s tackles for loss came in SEC play.

He could be one of the best defensive ends in the country in 2015, proficient against the run and the pass.

4. RG Jashon Robertson/LG Marcus Jackson

Robertson, a freshman All-American last season, was the team’s only offensive lineman to start in the same spot all 13 games (right guard). The 6-foot-3, 310-pond Robertson has taken a few snaps at center this spring, but make no mistake about it, he’ll enter the season right where he finished it in the TaxSlayer Bowl.

Jackson, a redshirt senior, has played in 36 career games with 17 starts. He’s by far the most experienced member of a young line, and it has showed this spring as he’s sat out due to injury.

The offensive line held the offense back last season — less so after Joshua Dobbs took over for Justin Worley at quarterback — and with the running game remaining such a big focus, losing either starting guard during the regular season would be a challenge.

3. RB Jalen Hurd

Hurd and junior-college transfer Alvin Kamara essentially are co-starters, nicknaming themselves the “CMG” — short for Chain-Moving Gang.

But the Vols must contend with a shallow backfield that almost literally doesn’t extend beyond those two. Hurd, a true sophomore, has seniority, as well as a near-900-yard season in 2014. But if either member of the newly-established CMG gets injured, as we’ve seen this spring, the complexion of the running game changes drastically.

Also, have you noticed a pattern yet? Several players on this list have been limited this spring, underscoring the likelihood that Tennessee’s relative lack of depth will come into play at one or more positions in ’15.

2. OLB Jalen Reeves-Maybin

Whomever starts at middle linebacker is anyone’s guess, as replacing A.J. Johnson is the most difficult task the defense faces this offseason.

Tennessee has a number of adequate bodies at the other outside linebacker spot, and Curt Maggitt could rotate there frmo defensive end on occasion. But Reeves-Maybin is the lone true star among the players the Vols will list at linebacker on the two-deep this fall.

The upcoming junior made 101 tackles last season, including 11 tackles for loss. The Vols would miss his production in the front seven if he got hurt. But he’s ranked ahead of Barnett on this list because UT is much thinner at linebacker than along the defensive line. The players the team does have at ‘backer are young and inexperienced, and the Vols really need JRM’s leadership and presence.

1. QB Joshua Dobbs

First, the team has no idea who will back up Dobbs. A trio of four-star true freshmen are vying for the role, and two of them — Jauan Jennings and Quinten Dormady — enrolled in January and went through spring practice. If Dobbs goes down, none of them will be close to ready to lead a team to an SEC East title.

Put it this way: Justin Worley, a senior starter, went down last season, and the offense improved by a wide margin. The difference between Worley, an experienced senior no matter how mediocre, and a true freshman would be even bigger.

Dobbs may not be the best player on the team, but the so-called CEO of the offense is covering up a huge pothole on the roster this fall, and Tennessee may be sunk if he were to get hurt.