TAMPA, Fla. -- The breakdowns that plagued the University of Wisconsin football team's defense at various points this season all showed up during Tueday's Outback Bowl, albeit less frequently.

Still, missed assignments, missed tackles and an inability to get off the field on third down all proved costly in a 21-17 loss to the Volunteers at Raymond James Stadium.

"It felt like in the first half we took a big step back," UW junior linebacker DeAndre Levy said. "It was very reminiscent of earlier in the season."

The Volunteers scored all of their points over the first two quarters, building a 21-14 halftime lead.

"We didn't execute. We knew what they were going to run, and they ran what we knew they were going to run," UW junior linebacker Jonathan Casillas said of the defensive performance in the first half. "It was just very disappointing just getting outexecuted and just having those mental errors and mental (busts)."

Tennessee's first big play came on its second possession when quarterback Erik Ainge found wide receiver Denarius Moore over the middle on a third-and-11. UW cornerback Josh Nettles went for the interception, but when he missed, Moore was able to turn upfield for a 40-yard gain that moved the ball to the UW 27. Tennessee capitalized six plays later when Gerald Jones scored on a 3-yard run.

The Volunteers' second touchdown came in the second quarter, when Ainge hooked up with receiver Josh Briscoe for a 29-yard score after Briscoe easily beat the coverage of UW safety Aubrey Pleasant.

One possession later, it was Casillas who was responsible for a coverage breakdown, losing track of Volunteers tight end Brad Cottam just long enough that Cottam was able to catch an Ainge pass across the middle and turn it into a 31-yard score with 6 minutes, 15 seconds to go before halftime.

"I overcommitted. He worked off where I was at," Casillas said. "It was just my fault. I took my eyes off my guy in my zone and he was running free down the field."

While the UW defense did a better job of tightening up in terms of tackling and being assignment-sure on its way to pitching a second-half shutout, the inability to stop Tennessee on third down in the fourth quarter allowed precious time to tick off the clock.

"That was probably our biggest challenge that we weren't (able) to overcome," UW coach Bret Bielema said.

Tennessee, which converted nine of 18 third downs overall, converted four of seven in the final quarter, including three of longer than 6 yards. And the Volunteers, who owned the ball for 10:14 of the fourth, also successfully converted a fourth down during that time.

"It was really disheartening," UW junior cornerback Jack Ikegwuonu said.

As was the final result.

"All due respect to Tennessee. They're a great team and they played very hard, they've got good players," Casillas said. "But I think we gave them some gimmes."