KNOXVILLE-Last year's football spring practice was all about adjusting - again - for the Tennessee Volunteers: adapting to a new coaching staff, new ways of doing things and new systems on offense and defense.

This spring will be less about learning new things and more about addressing old weaknesses: youth and a lack of depth. The Vols got contributions all over the field last season from freshmen and sophomores, and that group is working to take the next step in their progression.

Attrition from two coaching changes in two offseasons also leaves plenty of holes on the depth chart to be filled, either by guys stepping up this spring or freshmen coming in this summer.

The Vols open four weeks of spring practices Tuesday afternoon, culminating in the Orange & White Game at 2 p.m. on April 16.

1. Who takes the leadership reins?

Gone from last year is a senior class filled with guys who stuck through three coaching staffs, most notably linebacker Nick Reveiz, defensive end Chris Walker and tight end Luke Stocker. For a team that again will be relying on younger guys, the Vols certainly need to identify whoever will slide into those roles as leaders on both sides of the ball.

Tauren Poole, UT's 1,000-yard tailback from last season, is a candidate on offense. The quiet-natured Poole stuck through three staffs as well, though he almost decided to transfer after a sophomore season as the fourth-string tailback. He was elected by his teammates as a captain last season, and he'll be an elder on offense. It's also not inconceivable to see quarterback Tyler Bray step up vocally as a sophomore.

A defensive leader to fill Reveiz's big shoes as the glue guy might be a little bit more difficult. Linebacker Austin Johnson and defensive lineman Malik Jackson are a couple of seniors who might need to fill that void.

2. Who's going to catch Tyler Bray's passes?

Stocker and wide receivers Gerald Jones and Denarius Moore combined for 141 catches, 1,994 yards and 15 touchdowns as seniors last season. That's nearly 60 percent of UT's totals in those three categories, and the trio did the bulk of their damage once Bray took over under center.

Moore was the deep threat, Jones was the go-to-guy on third downs and Stocker was the reliable target whom defenses had to respect over the middle of the field. Aside from Bray's continuing development as a passer, how the Vols handle the departure of the three clutch catchers could determine whether the offense goes from good to great or even better.

Justin Hunter, who had seven touchdown catches and averaged 32 yards per reception as a freshman, figures to handle Moore's role. Former Calhoun (Ga.) standout Da'Rick Rogers will need to handle a bigger load, and Mychal Rivera takes over for Stocker. Receivers Zach Rogers, Matt Milton and DeMario Williams - a former basketball player at Middle Tennessee State who sat out last year after transferring - need to have big springs.

3. Can the running game get better?

Poole did run for more than 1,000 yards last season, but the overall running game was anything but reliable. Most of the nice numbers were aided by big runs where UT caught opponents in certain defenses.

The running will need to be more consistent this season to open things for Bray. Much of that will hinge on the continued growth of an offensive line that started three freshmen most of last season.

There's also an open door behind Poole for a complementary back. Sophomores Rajion Neal and Toney Williams will get the first looks there this spring before two promising freshmen arrive in the summer.

4. How will the back line look?

Janzen Jackson and Brent Brewer ended last season as UT's starting free and strong safeties. Neither is available as spring begins. Jackson withdrew from school for this semester because of personal issues that forced him to miss much of bowl practice, and Brewer is awaiting the completion of an investigation into his arrest for a domestic assault charge.

UT signed eight defensive backs in February's recruiting class, but only cornerback Justin Coleman is on campus for spring drills. That opens things for sophomore Dontavis Sapp and senior Rod Wilks. Prentiss Waggner, who began last season at safety before finishing at cornerback, has the versatility to move back to safety for spring.

5. What about the D-line?

Ben Martin's tough luck - a second torn Achilles' tendon - leaves the Vols with just three scholarship defensive ends: former Ooltewah star Jacques Smith, Corey Miller and Willie Bohannon.

Losses from an already thin defensive line from last year include ends Walker and Gerald Williams and tackle Victor Thomas. The Vols could move a couple of the ends they moved to tackle for last season back to end, but there's not a wealth of guys inside, either. Malik Jackson flourished as an undersized tackle last year. Marlon Walls still may not be 100 percent from his own Achilles' injury, and Montori Hughes is coming off a disappointing sophomore season.

Guys such as Steven Fowlkes, Arthur Jeffery, Rae Sykes, Greg Clark and former McCallie standout Joseph Ayres can help themselves and the team by showing some progress this spring.