ATLANTA — Cooper Taylor assumed he would sit out the 2008 season as a redshirt. He thought he was too thin at 185 pounds to make an immediate impact on Georgia Tech's defense.

Instead, Taylor surprised himself and others when he ranked second on the team with 69 tackles as a freshman. Now that he's added about 25 pounds of muscle, Taylor is a possible rising star for No. 15 Georgia Tech, which opens its season on Saturday against Jacksonville State.

Here's another surprise: The 6-foot-4 Taylor, now listed at 208 pounds, clocked the fastest time of any Georgia Tech player in the 40-yard dash in the offseason.

"I put out a good time, low 4.3," Taylor said. "I was always fast but I never thought I'd run that fast. For some reason, since I've started lifting really heavy weights, it has helped my explosion. I have more top-end speed than I had before. That's with more weight, too, which makes it better."

Taylor still looks slim. Lanky safeties aren't supposed to beat running backs, receivers and cornerbacks in sprints, and Taylor's 4.3 time left some teammates grumbling.

Georgia Tech coach Paul Johnson says the stopwatch doesn't lie.

"He's the fastest guy, I don't care what the other players say," Johnson said. "You put him on the watch and he had the fastest time."

Even Johnson was caught off-guard by Taylor's display of speed.

"Yeah it did," Johnson said. "He's got a long stride. He covers a lot of ground when he runs."

Taylor, the son of former Georgia Tech quarterback Jim Bob Taylor, made good use of his speed as a freshman. His forced fumble near the goal line helped Georgia Tech hold on for a 31-28 win over Florida State, and he led the Yellow Jackets with nine tackles in the 45-42 win over Georgia.

The Florida State and Georgia games were two of only three starts for Taylor as a freshman.

Taylor played several positions, including quarterback, at Atlanta's Marist School.

"I wanted him to be a quarterback just because I was," said Jim Bob Taylor, who was Georgia Tech's starting quarterback in 1982 before he spent the 1983 season with the NFL's Baltimore Colts.

Cooper Taylor "can definitely throw it," according to the elder Taylor, who added his son was better known for his speed.

"He was always pretty fast," said Jim Bob Taylor. "He grew up in the Alpharetta youth football league. They nicknamed him 'Corner Coop' because when he got on the corner very few kids were going to catch him."

Taylor is set to open the 2009 season as the starting free safety after beginning preseason drills at the "Wolf" position, a hybrid linebacker-safety spot in the Georgia Tech defensive scheme.

Dominique Reese and Rashaad Reid now are listed as the top two "Wolf" linebackers, leaving Taylor and Morgan Burnett as the starting safeties.

"I put on about 25 pounds since last season, but I'm still not built like a linebacker type player," Taylor said. "I think in time, definitely. For now it seems I fit at free safety the best."

Johnson says the experiments in the secondary were designed to find the Yellow Jackets' best 11 defensive players. No matter the mix, it's clear Taylor is one of the 11.

When backup quarterback Jaybo Shaw suffered a broken collarbone, there was brief mention that Taylor might be an emergency option at the position. But Taylor says he hasn't taken any snaps at quarterback and says he has no desire to move back to his father's old position.

"No sir," Taylor answered firmly. "I'm a defensive guy."

Taylor said his time at quarterback in high school has helped him read opposing quarterbacks.

"I guess I feel more comfortable being back there," he said. "I like being able to read and react. Having played quarterback, I can kind of know what they're going through in their mind. I just like when the pressure is on being able to stop somebody."

NOTES: Johnson said running back Roddy Jones, recovering from a dislocated wrist, returned to contact drills on Monday and may play on Saturday. Johnson said he may make a "game-time decision" on Jones, who rushed for 690 yards last season. ... Johnson said freshman receiver Stephen Hill, a top recruit, will play. Hill is listed as Demaryius Thomas's top backup. ... Wide receiver Tyler Melton is out with a left knee injury. Linebacker Kyle Jackson is out with a foot injury.