Former Tennessee Titans defensive lineman Tim Shaw was diagnosed with ALS, and first experienced debilitating symptoms in April.

"I would never say I am not afraid of anything,'' Shaw said Wednesday at Saint Thomas Sports Park, the Titans' team headquarters and practice facility. "When you look at what ALS has done to people, that is a scary process. So I am not scared to die, but the process is a little daunting."

Shaw, 30, retired from the NFL on his birthday earlier this year. He was released in 2013 by the Titans.

Because Shaw is under age 45, he would be awarded a maximum benefit of $5 million from the NFL under the proposed head injuries settlement.

A special-teams captain for the Titans, Shaw was a highly respected teammate. The NFL has changed rules on kickoff returns to protect against head injuries by eliminating "the wedge," a wide wall of blockers that requires kickoff coverage teams to "break" the wedge, mostly with full-force collisions.

In a video released by the Titans, Shaw participated in the Ice Bucket Challenge -- the social media rage designed to raise awareness for ALS, amyotrophic lateral sclerosis, also known as Lou Gehrig's disease.

"A year ago, I was playing NFL football," Shaw, 30, said in the short video. "I've recently been diagnosed with ALS. I'm here today to stand up and fight with all of you against this disease."

Shaw's diagnosis could prompt further investigation into the connection between football, head injuries and ALS. He was at the team facility Wednesday to watch former teammates and coaches accept the Ice Bucket Challenge.

"As a man you have a choice. What are you going to do? Are you going to stand up and fight for your life? Or are you going to accept what someone else tells you is reality and just fade away?" Shaw said. "As staggering as that news was and as shocking as it was to hear and to say, I made that choice to stand up and live life to the fullest like I believe I always have."

The National Institute for Occupational Safety and Health found in a 2012 study that NFL players are four times more likely to suffer and die from ALS than non-NFL players and a similarly high risk for Alzheimer's.

Known high-profile NFL cases of O.J. Brigance with the Baltimore Ravens and New Orleans Saints' Steve Gleason, who became major advocates for awareness of ALS.

Shaw was a fifth-round pick by the Carolina Panthers in 2007 out of Penn State and played one season with the Panthers, Jaguars and Bears before joining the Titans in 2010.

He played in all 16 games all three seasons in Tennessee as a special teams ace, starting three games at linebacker. He played in 80 games in six seasons.