ATLANTA — When Dan Mullen held his first team meeting as the new coach of the Florida Gators, there was a posture problem in the room.

“We had some guys slouching over while he was talking,” OLB CeCe Jefferson said. “He said some words to them and made them straighten up. It was like, ‘OK, we’ve got a new sheriff in town.’ He singled them out.”

Jefferson looked around and saw eyes wide open.

“You’d have thought Casper the Ghost went across the front of the room,” he said with a laugh.

That figurative “boo!” from the new head coach is preferable to the boos the players were hearing while going 4-7 last fall.

You could say Mullen is both the ghost of Florida glory past and the ghost of Florida glory future. The last time the Gators were great, he was part of it. He figures to be part of it the next time they’re great, too. Whenever that is.

That opening meeting is illustrative of a Mullen trait: he doesn’t wait long to make an impression. He brings a strong personality from Starkville to Gainesville.

Mullen has traded in his Yeezys for Jordans and his plucky overachiever program for a slumbering giant. If he packed his quarterback magic with him for the move from Mississippi State to Florida, the Gators might have made the best third-choice hire in a very long time.

Mullen arrived at his 10th Southeastern Conference media days Tuesday with customary bravado. After creating a tradition wearing the Adidas Yeezy sneakers with his suit to this event while coach of the Bulldogs, Mullen is contractually bound to switch to Nikes now.

“I got my swag on,” Mullen said.

After the flairless misery of 2017, this is a from-the-ground-up energy injection. Florida fans are very much hoping the swag that helped Mullen fashion a 69-46 record at traditional punching bag Mississippi State translates to their underachieving program. The last time the Gators were great was a decade ago, when Mullen was Urban Meyer’s offensive coordinator and they were winning a second national title in three years.

Then Meyer burned out, Will Muschamp muddled through four mediocre years and Jim McElwain failed to do the thing he was hired to do — reignite Florida’s famed firepower. With attendance down more than 1,100 per home game as the Gators averaged just 22.1 points per game, the stadium known as “The Swamp” had lost the joyous buzz that characterized the Meyer and Steve Spurrier Eras.

“I’m the opposite of Trump,” Mullen cracked. “I’m here to fill the Swamp, not drain the Swamp. … Getting the fan base back on board is going to be a big deal for us.”

Mullen has the job despite being a third-stringer on athletic director Scott Stricklin’s coaching search depth chart.

His first target was Chip Kelly, the unemployed former architect of the up-tempo Oregon attack. Kelly chose UCLA instead.

His second target was Scott Frost, who had worked under Kelly at Oregon and then took Central Florida from 0-12 to 13-0 in a matter of two years. Frost chose Nebraska instead.

That left Mullen, and while being rejected twice is a blow to Florida’s prestige, it still landed as accomplished a third choice as any athletic director is going to find. Mississippi State hadn’t had six straight winning seasons since the early 1940s until Mullen did it from 2010-15. His four years with nine or more wins are the most in the school’s modest history.

Mullen inherits an experienced team laden with players whose college careers have been characterized by unfulfilled hype — particularly on the offensive side of the ball. He brings a successful scheme to Gainesville and a remarkable track record with quarterbacks, from Chris Leak and Tim Tebow at Florida to Dak Prescott and Nick Fitzgerald at Mississippi State.

Whether the Gators’ offense as a whole and quarterback position in specific can be remade in a single season remains to be seen. But Mullen isn’t shying away from the challenge of creating an offense that maximizes the talents it has.

“There’s personnel everywhere,” he said. “Everyone has personnel. The job of the coach is to take the personnel and put them in position to be successful. We’re not going to be able to score points this year the way we did last year at Mississippi State (32 points per game) or in 2008 at Florida (43.6), probably.

“If I have a round peg and a square hole, I’m not going to keep slamming at it. I’m going to take the square peg and put it in a square hole. … The person that needs to change is me. And what we’ll do is change offense around the strength of the quarterbacks.”

Mullen’s flexibility doesn’t extend as far in matters beyond scheme. Program culture is non-negotiable — an emphasis on daily competition, a full-tilt approach, an obsession with details.

That includes posture during team meetings. Florida players probably will be telling ghost stories about Dan Mullen’s first meeting for years to come.

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