KNOXVILLE -- The last two times time the University of Tennessee has faced an up-tempo no-huddle spread offense similar to what it will see against Montana on Saturday, things ended poorly for the Volunteers.

Oregon slashed UT in a 35-point win last season with 447 yards of offense and 26 first downs, and Auburn did similar damage in 2009, racking up 459 yards and 24 first downs. The Grizzlies won't have comparable ability Saturday evening, but the tempo could create problems for a UT defense with seven new starters and three or four true freshmen.

"They've got a number of guys that are very good athletically in space, and as last year showed that's one of our areas of concern ... how well we'll tackle in space," defensive line coach Lance Thompson said Wednesday. "On short balls or underneath throws, when we finish our rush, we've got to turn and run and get some hits from the blindside, maybe create some turnovers.

"The big thing for us is always going to be tackling, because when you look at big plays and what you give up, if you don't tackle well that's usually where your big plays come."

Montana averaged 373.5 yards per game last season (UT averaged 363.8) and ranked 16th in the Football Championship Subdivision with almost 32 points per game. Second-year coach Robin Pflugrad coached for three seasons at Oregon before joining the Grizzlies' staff in 2009.

UT defensive coordinator Justin Wilcox said Montana's tempo limits how much opposing defenses are able to substitute players.

"It's hard to simulate during practice because it's something they do every day as part of their program," he said. "It's how they operate, is up-tempo pace, and so we've got to be ready to handle that. What that does is, if you want to sub and they're going up-tempo, you're not able to just because you don't want to be running in and out while they're snapping the ball.

"It affects us, meaning we've got to be able to play groups to all their personnel groups. We can't always one-for-one sub them if they're going at that up-tempo."

Practice update

The Vols practiced in shells Thursday morning and will have a walk-through today. ... Jimmy Stanton, UT's associate athletic director for communications, said after the open period of practice ended that cornerback-turned-receiver Naz Oliver will miss the season following surgery on a right-wrist injury he suffered during camp. ... Justin Hunter remained in a red noncontact jersey for the second day in a row as a precaution, but fellow receiver Matt Milton (concussion) was back in a white jersey. ... Geraldo Orta (shoulder surgery) participated during some individual drills, but the freshman defensive back resumed his routine of running on the side when team periods began.

The other five

Freshman early enrollee Marcus Jackson and redshirt sophomore JerQuari Schofield entered camp as co-starters at left guard, but Alex Bullard relegated both players to the second-team offensive line. But Jackson and Schofield might be the first guard and tackle, respectively, off the bench in case of an injury to one of UT's five starters.

"Those guys have been doing pretty good," offensive line coach Harry Hiestand said Wednesday. "They're working -- they're getting a lot of reps with the twos -- so they're seeing some of those same things."

Freshman left tackle Antonio Richardson was one of the biggest recruits the Vols signed in February, but the 6-foot-6, 325-pound Nashville native missed most of the first part of camp following shoulder surgery.

"[It's] very hard, very hard," Hiestand said. "He missed a lot of time, but he works hard and he's really determined to be a good player. It's just a matter of time."