Sylvester's leadership skills are appreciated by his teammates, who elected him as a captain — the only non-senior in a mix that includes Robert Conley, Brian Johnson and Brice McCain.

On the field, Sylvester has tallied five tackles-for-loss, four pass breakups and two forced fumbles.

Fotu, a sophomore, tops the linebackers with 5.5 stops behind the line of scrimmage.

The underclassmen have played like veterans on a Utah defensive unit that ranks second in the conference in four major statistical categories (rushing defense, pass efficiency defense, total defense and scoring defense).

The Utes have been particularly strong against the run, holding four opponents (Michigan, Utah State, Air Force and Weber State) to less than 60 yards rushing. They held the run-oriented Falcons to just 53 yards on the ground, 300 below their season average at the time and their lowest game total since 1980. Only three opposing backs have reached 100 yards rushing against Utah's defense this season. No one had more than 106.

— Dirk Facer

BYU'S RUNNING BACKS: Sophomore Harvey Unga, the Mountain West Conference's freshman of the year in 2007 (he scored the game-winning touchdown against Utah a year ago), is one of the Cougars' biggest offensive weapons. Though he has been banged up much of the season with shoulder and stinger injuries, he's still managed to rush 208 times for 945 yards (averaging 4.5 yards per carry), needing 55 yards to break the 1,000-yard barrier for the second straight season.

Unga has scored eight touchdowns on the ground this season. He is also the Cougars' third-leading receiver, catching 38 passes for 298 yards and four TDs. Unga has a knack for making big plays, such as his season-high 40-yard touchdown run in the fourth quarter against Colorado State.

Prior to the season, one area of concern for the offense was replacing Manase Tonga, who was suspended for the year. Senior Fui Vakapuna has more than filled that void, embracing the role as Unga's lead blocker. He has also done a good job protecting Max Hall from blitzes. Vakapuna has rushed 49 times for 225 yards, averaging 4.6 yards per carry and he's scored two of his three touchdowns in the last two games. He's also caught nine passes for 64 yards and a TD.

Other backs in the mix include senior Wayne Latu, who has rushed for 51 yards on 10 carries, and freshmen J.J. DiLuigi (13 carries for 48 yards) and Bryan Kariya (eight carries 35 yards). Both Latu and DiLuigi have both fumbled the ball away twice this season.