"They have two really fine backs that run hard, run fast," the Vol coach said. "They come out a lot of places."
Brown and Moreno pose quite a challenge for a Tennessee defense that missed 22 tackles in Game 1 at Cal and 16 more in Game 3 at Florida. Asked if he can remember a time when tackling was such a concern, Fulmer shook his head.
"No," he said, adding that the key is "the front taking care of their responsibility and not allowing people to empty on the linebackers right away. It's not just poor tackling, although some of the obvious ones – when a safety misses – have ended up being big plays."
Even though the Vols' front four hasn't clogged the middle on a consistent basis, the linebackers and defensive backs have failed to bring down opposing ball-carriers far too often. That's why Tennessee spent its recent open-date week working on the basics of tackling.
"We have really worked hard on improving that," Fulmer said. "We've gotten better as we've gone along but we're not where we need to be."
After five weeks spent fielding questions about Tennessee's tackling problems, Vol defensive coordinator John Chavis is somewhat weary of them.
"There's not going to be any football team, when you're playing against good competition, that's going to make every tackle," he said. "But we're not pleased with where we are. In the past we've been a very fine-tackling football team. We need to grow there, and we are growing there. We made some progress in the open week to get some of those things addressed."
Asked if he has pinpointed the gist of the Vols' tackling problems, Chavis shrugged.
"It's a combination of things," he replied, "but the big word is confidence. When you know what you're doing and you're able to go out and play full-speed you can do a lot of things better."
Fulmer conceded that the confidence level of Tennessee's defense is probably a little low these days.
"After somebody gets beat up so much about it, human nature takes over a little bit and you become a little on the hesitant side," the head man said. "You can't be hesitant, particularly with backs like we're playing right now. You've got to be able to shoot your guns and make plays."
One Vol who has been making surprisingly few plays this fall is senior defensive tackle J.T. Mapu. Considered a budding star as a sophomore in 2003, he has been a non-factor since returning from a two-year Mormon mission in the fall of 2006. After losing his first-team job, however, he has shown some flashes of his old form.
"I'm really happy with J.T. Mapu and the way he has taken the challenge," Fulmer said. "He has had his best two weeks of practice since he's been back from his mission. He has pushed himself at least into the rotation, if not back into a starting position."
Another player who has not been playing up to expectations is Jerod Mayo. He starred as a weakside linebacker in 2006 but has not distinguished himself since moving to the middle in 2007. Asked if Mayo's struggles have negatively impacted the Vol defense, Fulmer shook his head.
"He's at a place where they can't run away from him ... in the middle," the head man said. "We do move him out (to end) in the nickel package and let him come off the edge and do some things. We want our best guys on the field, and he's done a good job."
To date, Tennessee's "best guys" have surrendered 115 points through the first four outings, an average of 29 points per game. That's not counting three touchdowns opponents scored on Vol turnovers and two more TDs on punt returns.
"Hopefully," Fulmer said, "we haven't seen the best of this Tennessee defense yet."
Obviously, that comment wasn't meant to inspire confidence, either.