"It's amazing watching them run the speed sweep," Chavis said. "They never blocked the defensive end because they didn't think the defensive end could make the play. And they were right ... he couldn't.
"Harvin gives you that. You can block 10 and let one guy go. When you can do that, you've got pretty good odds on your side."
Essentially, Harvin's 4.3 speed puts the spread in Florida's Spread Offense all by himself. He is so fast that opposing defenses have to spread out just to try and keep him from getting outside. This, of course, creates wider running lanes in the middle of the field for him to zoom through.
"You can't give him an open gap," Vol defensive tackles coach Dan Brooks noted. "If he breaks it open, nobody – not just Tennessee – has got folks that can run him down."
Although Chavis describes Harvin's speed as "unbelievable," the Florida flash also has a knack for seeing creases and cutting through them before they close.
"He's got good vision, sees the seam and takes it," Brooks said. "That's the problem: You've got to contain him on the perimeter but he's a good inside runner, too. That's the biggest thing – trying to keep him contained at the line of scrimmage – because if he breaks out you're not going to catch him."
A lot of guys have sprinter speed and football aspirations but Harvin is one of those rare athletes who has sprinter speed and football skills. He's in his element on the gridiron, not just on the track.
"There's been so many great backs in this league – the guys at Auburn, at Georgia, at so many other places – and Harvin is one," Brooks said. "He has the added dimension of lining up all kinds of places. He'll even line up and take the snap at quarterback. They do a good job of moving him around and making you defend a lot of different things"
Chavis touched on the same theme.
"He's a guy they can line up at split end, go one-on-one with your best corner and you're not going to match up. And he's a guy they can line up in the backfield.
"He's all over the field. He's an X receiver one snap, he's a tailback the next snap. They put him in motion, do a lot of things to get the ball in his hands. You have to approach it with a balanced defense because you never know where he's going to line up."
Tennessee had no answer for Harvin in the 2007 game at Gainesville. He caught four passes for 120 yards (30.0 per catch) and rushed nine times for 75 yards (8.3 per attempt) and a touchdown. Unfortunately for the Vols, he poses even more of a threat now that he has bulked up from 187 pounds to 195.
"He ran the ball inside last year, and that's more of a concern now that he's stronger," Brooks said. "I fully expect him to be a better player than he was a year ago when we played him."
Even with the speed to get outside, Harvin is most dangerous when he is running north/south, rather than laterally. Once he gets a head of steam going forward it's six points.
"His raw speed is the big thing," Brooks noted. "All you can do is just try not to let him get that open gap to where he gets full-speed."