MEMPHIS -- DeAngelo Williams, the University of Memphis's All-America running back, was on the sidelines, reduced to spectator status because of a bum left ankle.

The Tigers, minutes away from playing in-state rival Tennessee at Neyland Stadium, had intended to let the nation's leading rusher test his skills against one of the SEC's top defensive lines.

Instead, with Williams hobbled, the Tigers turned to sophomore Joseph Doss, the rugged, dependable back from Memphis Melrose High School. Doss didn't disappoint.

Doss met the challenge -- and the Vols' defensive front -- head on, gaining a team-high 77 yards to put the Tigers in position for a win. Memphis led, 16-14, entering the fourth quarter, but two James Wilhoit field goals gave the Vols a come-from-behind victory.

When the Tigers (1-2) host the Vols (2-1) at noon Saturday at Liberty Bowl Memorial Stadium, Doss will be in a different role. He'll be the team's starting tailback, hoping to duplicate, or surpass, last year's totals.

With Williams having departed for the NFL, Doss has moved comfortably into the No. 1 tailback position, a transition aided by his surprise start at Tennessee.

''Last year, as a sophomore, getting a chance to play in that environment, that performance was a confidence-booster,'' Doss said. ''It was one of those things you need in life.''

To keep pace with an improved Tennessee team, Tiger coach Tommy West said Memphis will need Doss and other running backs to play well.

''We've got to be able to run the ball,'' West said. ''If we get in this one and we can't run it, it could get ugly. Our offense is going to have to help us a little bit.''

When the Tigers traveled to Knoxville a year ago, it was with a team geared to running the ball. Memphis had lost its top two quarterbacks -- Patrick Byrne and Will Hudgens -- to season-ending injuries and evolved into one of the nation's top running teams behind Williams.

This year Memphis has done an about face. Transfer quarterback Martin Hankins is averaging 256.7 yards passing, which ranks third in Conference USA, and Doss is the league's third-leading rusher. But the Tigers are averaging only 114.3 yards rushing per game, a total that ranks 79th nationally.

Memphis averaged 267.9 yards rushing -- a modern-day school record -- a year ago.

''What I want to be offensively is just as good a running team (as last year) that can also throw it,'' West said. ''With being able to throw the ball better than we have, we should be as good a running team as we were ... or better.

''We've got to do both in this game. But, my point is, if we average two yards a rush it's going to be really hard on us.''

In the aftermath of the firing of defensive coordinator Joe Lee Dunn last week, the Tigers used the off week to install a new defense and emphasize the running game.

''I felt like we did last week (in practice),'' West said. ''I thought our young backs ... (Miguel) Barnes and (T.J.) Pitts worked hard. We worked them hard, them and Greg Hinds, trying to decide who will be our second or third back. I thought they did a nice job. I thought they ran downhill a little bit harder than they have.''

Pitts, Barnes and Hinds have combined for nine rushes for 29 yards this season. Barnes, who was suspended indefinitely before the East Carolina game two week ago, hasn't been re-instated, but has been practicing. Pitts battled early-season hamstring injuries, but has returned to back up Doss and return kickoffs. Jamarcus Gaither played extensively against Chattanooga when Doss was hampered by an ankle injury.

Doss carried 23 times in the opener against Ole Miss and gained a career-best 112 yards. He also had 23 rushes, for 99 yards, in a 35-20 loss at East Carolina on Sept. 16. His 75.7 yards-per-game average ranks third in C-USA.

''I like our backs,'' West said. ''The key to this one won't be our backs. Our backs will play hard and they'll run well. The key will be can we block their front guys. They're good up front, real good. They're good on defense.

''I know what kind of players Florida has offensively. They get after them really good. They're good on defense, but they always are because (defensive coordinator) John (Chavis) does a real good job.''