GAINESVILLE, Fla. — Florida linebacker Brandon Spikes heard the whispers all last season.

He listened to them again this spring and throughout the summer.

What's wrong with Florida's defense? Why do those guys miss so many tackles? Where's the pass rush? Why is the secondary getting burned so often?

"People questioned us last year," Spikes said. "It won't be like that again."

The Gators are counting on it.

Although Heisman Trophy winner Tim Tebow and speedster Percy Harvin get most of the attention, and rightfully so, No. 5 Florida realizes its success this season probably will hinge on defense.

The Gators, who open Aug. 30 against Hawaii, gave up 28 or more points six times in 2007. They also had the lead in three of their four losses. In the other, Florida and Auburn were tied at 17 before the Tigers used a late drive to set up a game-winning field goal.

The problems were obvious. The Gators failed to get steady pressure on quarterbacks, struggled to stop the run at times, and maybe the most glaring weakness, were all those blown assignments in the secondary.

The solutions might be evident, too.

"You've got to have guys that are not afraid to make mistakes," defensive coordinator Charlie Strong said. "When you have guys that think about making mistakes, all they do is make mistakes. You need guys not worried about the 'what ifs."'

Strong's unit showed signs of progress down the stretch last season, winning four in row and getting solid defensive efforts against Vanderbilt and Florida State.

But the defense was downright humbled against Michigan in the Capital One Bowl.

The Wolverines racked up 524 yards of offense and scored on seven of 13 possessions. It could have been worse, too, had Chad Henne not thrown two interceptions and Mike Hart not fumbled twice near the goal line.

The Gators couldn't tackle Hart, couldn't pressure Henne and couldn't cover Adrian Arrington or Mario Manningham. The result was a 41-35 loss that has haunted defensive players ever since.

Florida's coaching staff has shown highlights — lowlights, really — throughout the offseason to remind players how much room they have for improvement.

Spikes wanted to turn away at times, but eventually decided to use it into a motivational tool.

"There is always room for improvement," Spikes said. "I wasn't satisfied. I felt like I needed to make more plays to change the game. When we needed a play on third down, I just didn't get the job done. I am just trying to get the job done this year and get off the field. ... When someone else doesn't make it, I need to make it."

Although the coaches want Spikes to be a more vocal leader, they also are looking for others to step up.

Safety Major Wright needs to tackle better. Cornerbacks Joe Haden and Wondy Pierre-Louis need to cover tighter. And the defensive line needs to be more production.

If that happens, Florida believes the defense will move closer to being on par with its high-scoring offense and give the team a better chance of getting back to the Southeastern Conference championship game.

"We feel we can be much stronger than we were a year ago," sophomore cornerback Moses Jenkins said.

It starts along the defensive line, where true freshmen Omar Hunter and Matt Patchan are expected to make immediate contributions.

"There's some pressure, but I love pressure," said Hunter, a Parade All-American from Buford, Ga. "I like those situations where you have to come in and you being the guy everybody's looking forward to playing and helping out the defense. That's what I want to do."

Freshman safety Will Hill may have to do the same.

Florida has endured several setbacks at that position. The Gators lost starter Tony Joiner and backup Kyle Jackson to graduation. Then Jerimy Finch transferred, Jamar Hornsby was kicked off the team for allegedly using the credit card of a deceased student, and Dorian Munroe and John Curtis had season-ending knee surgery.

And incoming freshman Dee Finley, expected to compete for playing time, did not qualify academically and enrolled at a prep school.

All the losses have people questioning the defense — again.

Not Spikes.

"Guys are growing up and taking stuff to heart, building chemistry and knowing we can depend on each other," he said. "And if we keep taking strides, we're going to be just fine."