OXFORD, Miss. -- Deterrian "D.T." Shackelford sat in one of the Ole Miss football offices Monday and talked about all the things he had done since he arrived at Ole Miss in 2009. He also talked about all the things he still wanted to do.

Shackelford, a rare sixth-year senior, has already received his undergraduate degree in liberal arts and his Master's degree in higher education. He's been on mission trips to Panama and Haiti. He eventually wants to get his Ph.D. and become a college athletic director, but not before he tries his luck in the NFL.

"There's a lot of different stuff I want to do, but I do still want to put on my cleats," the veteran linebacker said with a laugh.

There was a time, though, when some thought Shackelford would never put on his cleats again.

Determination and hard work have always come second-nature to Shackelford.

Former Ole Miss coach Houston Nutt still remembers the first time he visited Shackelford's high school. The high school coach told Nutt that this was the hardest-working player he's ever had. Nutt heard that from a lot of high school coaches, but when he saw Shackelford go through a workout, he thought to himself, "My goodness, this guy is something else."

"It's real simple," Nutt said. "I think anybody will tell you: There's not going to be one that gives more effort. There's not going to be one that cares about his teammates, about his school, more than D.T. Shackelford."

The Alabama product eventually signed with the Rebels, and in his first two years, he was one of the better players on their defense. He earned freshman All-SEC honors and led the team in sacks as a sophomore.

That next spring, Shackelford's playing career took a wrong turn. He was doing simple position drills in practice when he tore his ACL. It wasn't part of the plan. He'd have to sit out at least five months, which meant he wouldn't be back until the middle of the season.

"It was crazy because I had never been injured," Shackelford said. "I had never really faced an injury, especially an injury of that magnitude. All the time in football you get nicked and bruised up. 'I'm alright. I'm alright. Put some dirt on it, you'll be alright.' But that one I wasn't alright."

"He was down, but he just kept telling me, 'Coach, you know I'm going to be back,'" Nutt said. "I said, 'Oh yeah, there's no doubt in my mind that you'll be back.'"

The only problem is that Shackelford didn't come back, at least not under Nutt. He re-tore the same ACL five months later and wouldn't play in a game until 2013. He missed two full seasons with the injury.

"Of course you question it," Shackelford said. "You wonder, 'What is going on?' But I've always been assured that when God has his hands on you, he has the plan, not me. I was able to get to a point where I accepted the situation for what it was and was able to move on."

It was at that point when he realized that football can be taken away at any time. It's temporary.

But rather than sulk and feel sorry for himself, Shackelford made it a point to help his teammates. He never missed a practice. He never missed a game. He became a leader off the field with what he said, how he acted and how he carried himself.

"Nobody really looked at me as D.T. Shackelford the football player then," he said. "It was D.T. Shackelford the person."

When Hugh Freeze arrived at Ole Miss in December 2011, Shackelford had just reinjured his knee. The first-year coach didn't know Shackelford, but when it came time to award the Chucky Mullins Courage Award the next spring, Freeze knew to whom he was giving it.

In fact, in the three years Freeze has handed out the award, Shackelford has made history twice. In 2012, he was the first junior to receive the honor, and this past spring he became the first repeat winner.

"We could talk all day about the qualities that should be represented with wearing that jersey that Chucky wore and what qualities make up the right guy." Freeze said Monday. "But one thing I know about the right kind of people is that they finish. I don't think anybody can debate that one. That doesn't mean they don't fall off cliffs, fall down or make mistakes. But you get up and you finish. I think D.T. models that pretty dang well."

It wasn't easy, but Shackelford will finish his football career at Ole Miss. And it's only fitting that he's wearing Mullins' No. 38 his final season. It's also fitting that the Rebels are having one of their best seasons in school history.

Shackelford is the starting middle linebacker and the unquestioned leader for a defense that ranks top five in almost every category. His nicknames might range from "no knees" to "grandpa" to "old head," but his teammates understand how important he is to that unit.

"Shack's our emotional leader," cornerback Mike Hilton said. "He's the one that keeps us going. Even if he doesn't make a play, he's the first one to come over, jump and get rowdy. He's a crowd favorite, so I'm happy to have him on this side."

Ole Miss is currently ranked No. 3 and is one of only three Power 5 unbeaten teams left, but when Shackelford talked Monday about the things he still wanted to do, winning a national championship didn't come up.

It wasn't because he doesn't want to win one or because he doesn't think the Rebels can. He's just focused on the next game and thankful to be playing in it.

And after what he's been through, how can you blame him?