The defensive scheme has changed.

The depth chart has been altered to reflect the change.

And practices have been conducted at an increased tempo.

How it plays out Saturday when Memphis plays host to 15th-ranked Tennessee at noon (TV: ESPN) at Liberty Bowl Memorial Stadium is head coach and new defensive coordinator Tommy West's guess.

West dismissed defensive coordinator Joe Lee Dunn last week, citing a loss of confidence in a blitzing, attacking scheme that wasn't bringing enough pressure.

West, in his sixth season at Memphis, assumed control of the defense and spent the off-week installing a new system -- a base 4-3 -- designed to re-introduce pressure.

"It was a little bit harder than I thought it would be getting certain things in because it's a total change," West said. "But there's no doubt in my mind we got better (during practice last week). Of course, we started at zero.

"We'll try to keep a couple of things off the old package. But putting in a total new package, your base package (is hard). Had we not had an open date there's absolutely no way that we could have done it. None."

Memphis (1-2) enters Saturday's game ranked last in Conference USA in sacks (two) and 10th in rushing defense (185 yards per game).

West said he hopes the unit, which has gone through a crash course learning the new system and its terminology, will show improvement as the game progresses.

The depth chart for the Tennessee game reflects the new look. There's not a three-man front, but a four-man defensive line of left end Corey Mills, left tackle Clinton McDonald, right tackle Rubio Phillips and right end Jada Brown. Rod Smith has moved from outside linebacker to strong safety, backing up Derek Clenin.

And there's not a right cat and left cat safety to go along with free safety Wesley Smith. There're two cornerbacks (Dustin Lopez and Brandon McDonald) and two safeties (Smith and Clenin).

"We'll be very simple to try and not let them just run by us or be wide open because we bust a coverage or do something we're not supposed to do," West said. "We've got to be simple for our guys, but then No. 1 (Tennessee receiver Jayson Swain) and No. 3 (Tennessee receiver Robert Meachem) for them are great players, maybe the best pair of wideouts that I've played against in a long time, maybe ever. They are really good. And I usually don't overrate players."

Brandon McDonald said it was an interesting week of practice with West as defensive coordinator. The Tigers conducted several intense workouts last week with the No. 1 offense practicing against the No. 1 defense -- something rarely done during the regular season -- and are expected to have the same pairing at practice this week.

"He's trying to get everybody (on defense) to run and get excited about playing," McDonald said. "I think we have been more fired up and running to the football. Coach West is doing his best to put us in position to make plays."

McDonald said the biggest change in practices with West running the defense has been the tempo of the workouts.

"Practice was intense before, but it wasn't as intense as this past week," he said.

West is counting on the tempo to create more havoc. Memphis has forced a league-low four turnovers in three games.

"At practice, they've learned we play at a lot faster tempo than we've played at," West said. "I know our defensive players understand that, right now. I'm encouraged. I think that'll be better. We'll have more people around the ball and, hopefully, we'll get some hits and try to create some turnovers."

Wesley Smith, the three-time all-conference player from Oxford, Miss., said the only defensive coordinator he's played for has been Dunn. He's gone through an acclimation period.

"It's been like taking class for the first time," Smith said. "You've got to learn what to do ... and then go out and perform.

"It was kind of overwhelming the first day because we didn't know what we were getting into. It was new to everybody. But now ... it's kind of settling in."

West said he'd like to mix coverages and play both three- and four-man fronts.

"The big thing is we can play a base defense and be sound," West said. "And then we can play a pressure defense and get pressure.

"Where I was disappointed with our defense previously is when we did pressure we didn't get pressure. We've got to be able to get around this quarterback ... we've got to get to him and hit him."