IRVING – Aaron O'Neal remains an integral part of Missouri's football program, 29 months after he died in a voluntary workout.

As the Tigers were ending practice Saturday for the AT&T Cotton Bowl, the players gathered near midfield at Texas Stadium.

In unison, they yelled: "A.O.!"

The post-practice ritual is only one of the ways Missouri has preserved O'Neal's memory.

His locker remains enclosed in glass in the Missouri locker room in Columbia, Mo. O'Neal has a biographical page in the Missouri media guide, like the other members of his recruiting class. On the road, the Tigers bring a sign that includes O'Neal's initials and his uniform number (25) and place it outside their locker room.

"Everything we do is always about him," coach Gary Pinkel said. "We finish anything we do here, we remind ourselves of that all the time.

"That was a tragedy and difficult for everybody. He would be ... so proud of everybody and what we accomplished."

O'Neal, a redshirt freshman linebacker from St. Louis, died July 12, 2005, shortly after collapsing during a workout at Faurot Field. A four-sport star in high school, he oozed potential and promise behind an omnipresent smile.

Lorenzo Williams, now an all-Big 12 defensive tackle, was among those at the workout. He finds it hard to talk about the day.

"We were going through a workout ... and then my friend was dead," Williams said.

The day wasn't particularly hot, Williams said, nor was the session especially taxing.

The medical examiner's report said O'Neal died from lymphocytic meningitis. The finding has been disputed, with others suggesting sickle cell syndrome as a possible factor.

O'Neal's parents filed a lawsuit against the university and a number of athletic and training personnel, including Pinkel and athletic director Mike Alden.

A pending lawsuit would have prompted some schools to distance themselves from the situation. But Missouri has embraced O'Neal and his legacy.

Pinkel said last week that he let down his guard after O'Neal's death, becoming more accessible. Players confirmed the change.

Safety William Moore said the team came together, almost like a family.

"When it happened, it devastated a lot of guys, especially in my class, because we came in with him," defensive lineman Stryker Sulak said. "It brought us closer [knowing] anything can be taken from you at any point in time. You're not guaranteed anything."

O'Neal's memory remains an inspiration.

"It is as big as it ever was. ... We don't think we would be here without him," Williams said. "We keep him in our prayers. There are guys who talk to him daily. We definitely keep him with us wherever we go."

The Associated Press contributed to this report.