GAINESVILLE -- When cornerback Joe Haden first arrived at the University of Florida, he had visions of playing quarterback.

Haden stepped on the practice field in 2007, took one look at Tim Tebow and said, ``Next.''

Next was receiver. That didn't work either. At the time, UF had a player named Percy Harvin.

``I was behind Percy, so that was another one,'' Haden said.

Haden, an athletic freshman from Olney, Md., wasn't satisfied with waiting. He knew he could contribute immediately, but didn't know where. Florida coach Urban Meyer suggested defense. Haden, who set records in Maryland as a dual-threat quarterback, thought for about a second and then replied, ``So, now I have to guard Percy?''

After talking the idea over with his father, Haden agreed to make the switch from offense to defense. It appears to have been a good decision. Haden, a junior, enters Saturday's Southeastern Conference championship against No. 2 Alabama (12-0) as one of the top defensive backs in the country. He's a finalist for the Jim Thorpe Award and might be the best defender on arguably the best defense in the country. Top-ranked Florida (12-0) is ranked No. 1 in the nation in passing defense, allowing opponents an average of 143.17 yards through the air.

``Coming in as a freshman I just wanted to get on the field and help the team any way that I could,'' Haden said. ``And everything has been, so far, more than what I expected.''

Haden not only made a smooth transition to defense as a freshman, he became the first true freshman cornerback in school history to start the season opener. Now, three seasons later, Haden is projected to be one of the top cornerbacks selected in the 2010 NFL Draft and possibly a top 10 pick. All indications suggest that Haden will forgo his senior year at Florida and declare himself eligible for the draft.

Haden and fellow UF cornerback Janoris Jenkins have shut down some of the SEC's top receivers this season. Georgia star A.J. Green only managed three receptions against the Gators. On Saturday, Haden and Jenkins will face their most difficult challenge of the season, limiting Alabama sophomore receiver Julio Jones, a 6-4, 210-pound superstar who had five receptions for 124 yards against Florida during last season's SEC championship game. Florida defeated Alabama 31-20, on the way to the school's third national championship.

``He'll have his hands full with that big ol' receiver, Julio,'' Meyer said.

Alabama turned to Jones last week when the Crimson Tide needed a fourth-quarter score to come from behind and defeat rival Auburn. On Alabama's game-winning drive, Jones had four receptions for 33 yards, including two important third-down receptions. Shutting down Jones will be a point of emphasis for the Gators' defense this week during practice.

``Me and Janoris just really look forward to playing against good receivers because it really shows our talent and it just gives us another challenge out there,'' Haden said. ``Julio is big, strong, fast and we look forward to covering him.''

Haden is second among Florida defenders with 59 tackles but leads the Gators in solo stops (46). He has recorded three sacks this season and leads the team in interceptions (seven) and pass defenses (seven). He also has forced two fumbles. With a vertical leap measured above 40 inches and a 40-yard dash time around 4.3 seconds, Haden is considered among the best athletes in college football.

``He's got a Tebow-type work ethic,'' Meyer said. ``He did shock us when we first got him. We thought he would be a very good offensive player, but he comes in and starts three years at corner. He's blessed -- has a lot of freakish ability.''

Meyer's trust in Haden has earned him several important roles on the Gators' special teams units. He's a gunner on the punt-return team and on Saturday will play the safety position on kickoff returns to prevent a touchdown return from Alabama return specialist Javier Arenas.

``I don't think anybody has played any better than Joe,'' Meyer said.

``He's a force for us.''