ORONO — Trevor Bates wore No. 9 on the back of his University of Maine football jersey and a smile on his face. It was media day several weeks ago and if he understood how the grin undermined the significance of his new number, he didn’t care.

Saturday, Bates will run onto the turf at Alfond Stadium for the season opener with Norfolk State, wearing No. 9 for the first time in a game. The smile will be gone but not the attention paid to No. 9.

“I have to live up to the number,” said Bates. “I know what it means. Everyone on the team does.”

Only the toughest of Maine’s defensive players gets to wear No. 9. The number is handed down from one tough guy to the next by the player who can no longer wear it because he graduated or used up his college eligibility.

Bates, who played football at Westbrook High, couldn’t ask to wear it. He had to earn it, hoping Michael Cole, last year’s No. 9 and the senior defensive end, noticed and appreciated.

After each season ends, departing players give something tangible, something funny and something from the heart to those players returning to the team. Call it a living will.

Cole gave Bates the No. 9 to wear. It was something from the heart.

“I wanted that 9,” said Bates. “I knew what I had to do to get it. I had to work hard, play hard. I had to be an example. When the season was over I kind of thought I had a good chance.”

Put aside the X’s and O’s in the playbooks and on the chalkboards. Football is played with emotion and at Maine the passing of No. 9 carries its own unique expectations.

Wear No. 9 and you’re expected to become a hybrid linebacker-defensive end. Go after the quarterback, close running lanes, cover receivers. Be the player your teammates rally around on defense. In the parlance of Maine football you’re the Stud.

The legacy of No. 9 is relatively short. Matt King asked for it shortly after he arrived from Stoughton, Massachusetts, in 2002.

“I was always a single-digit guy,” said King. “I liked the way it looked. Coach (Jack Cosgrove) told me it was a wide receiver number. I said that’s OK, I’m going to turn it into a defensive number.”

King did, leading the Football Championship Subdivision (formerly Division 1-AA) in sacks and tackles for yardage lost in his senior year.

He was an All-American pick. He signed as a free agent with the New York Jets and later the Pittsburgh Steelers. He returned to Maine several years ago and is its strength, speed and conditioning coach.

Before he left Maine, King gave No. 9 to Jovan Belcher, who was signed by the Kansas City Chiefs and had a promising NFL career. In 2012, Belcher killed the mother of his child and took his own life in a horrific day that left scars.

Jordan Stevens, the outstanding defensive player from Mt. Blue High in Farmington, was next to wear No. 9. When he graduated he told Cosgrove he couldn’t find an underclassman who fit the No. 9 profile. Cosgrove later assigned the number to Doug Alston from New Jersey, who battled back spasms to become a leader on defense. The number was passed to Cole and now to Bates.

“Trevor asked if I had any tips for him now that he’s wearing No. 9,” said King. “I told him to be himself. This is about potential and character and the other stuff, and he’s already proven that.”

Bates is the typical Maine success story. Few saw him coming. He was a three-sport athlete at Westbrook. In football he played various positions as the program struggled to remain competitive in Class A. Cosgrove loved Bates’ athleticism and sense of the game but wasn’t sure where he’d fit.

After a redshirt season, Bates was willed the No. 92 by Raibonne Charles, the tough defensive tackle and character guy from Windham. Bates grew into that number. Now he wears No. 9.

It’s a good fit.