The Vols are allowing 5.5 yards per carry and 225.9 yards rushing per game to rank last in the Southeastern Conference in both categories. Even the maligned 2012 defense that statistically ranked among the worst in school history allowed fewer yards rushing per game (188.9) and yards per carry (4.8).
They're on pace to allow the most yards rushing per game of any Tennessee team since the 1986 squad gave up 232.1 per game. Tennessee hasn't yielded as many as 5.5 yards per carry over an entire season since at least 1950, the earliest year the school has those statistics on file.
"It's definitely fixable," sophomore safety Brian Randolph said. "It's not a talent thing."
Tennessee (4-6, 1-5 SEC) has a good chance of improving its woeful statistics in run defense during its final two regular-season games Nov. 23 against Vanderbilt and Nov. 30 at Kentucky. Vanderbilt ranks last in the SEC with 139.8 yards rushing per game. Kentucky is 12th out of 14 SEC teams with 159.1 yards rushing per game.
"It's definitely disappointing," senior defensive end Corey Miller said. "We've had our letdown days. We've had our sad days. We've come together as a defensive line and we've talked about it. We've discussed the past... what Tennessee means to us. It's all a mentality we've got to bring."
Some of the problems are easy to understand.
Tennessee's defense lacks overall speed. The depth of the front seven was decimated by injuries to tackle Trevarris Saulsberry and linebacker Curt Maggitt plus the ineligibility of tackle Maurice Couch.
The Vols have faced a brutal schedule that included seven ranked opponents in an eight-game stretch. Tennessee's defense also has dealt with a lack of stability. Steve Stripling is the Vols' sixth defensive line coach in as many years. John Jancek is Tennessee's fifth defensive coordinator during that stretch.
But instead of improving, Tennessee's run defense has gotten worse during its current three-game losing streak. The Vols have allowed 329 yards rushing per game and 6.9 yards per carry during that skid while being outscored 131-36 by top-ranked Alabama, No. 9 Missouri and No. 7 Auburn.
The Vols hit bottom last week by giving up 444 yards rushing in a 55-23 loss to Auburn. They also allowed Auburn to score on a kickoff return and punt return, as the Tigers breezed to victory without completing a pass after the first quarter.
"It's just the overall fundamentals," Tennessee coach Butch Jones said. "I think the theme was tackling - not just on defense but special teams as well - being a better tackling football team and also swarming to the football. You become a better tackling football team when you have 11 hats to the football."
Tackling has been a major emphasis during the Vols' bye-week practices.
"Until we become a better tackling defense, we're going to suffer," Jancek said. "You saw the results of that on Saturday - guys in position but (we) couldn't get them on the ground."
Tennessee has been particularly vulnerable against mobile quarterbacks.
Auburn's Nick Marshall rushed for 214 yards against the Vols last week. Tennessee allowed Missouri's Maty Mauk to run for 114 yards a week earlier. Florida's Tyler Murphy rushed for 84 yards and South Carolina's Connor Shaw ran for 78 yards against Tennessee this season.
The off week gives the Vols one last chance to turn things around.
"We're all sitting here asking ourselves the same question, and that's, 'Why?' " Miller said. "The question is, 'Why?' every time. We come into the film room every day Monday and it's like, 'Why? Why? Why?' Basically, what we're trying to do is fix the whys, come out here and be productive."