Sept. 9 (UPI) -- Pittsburgh Steelers star linebacker Ryan Shazier, who suffered a severe spinal cord injury that initially left him unable to walk, has officially retired from football.
The 28-year-old Shazier made the announcement in a video posted on social media Wednesday.
"When I was five years old, I made the greatest discovery of my life," Shazier said in the Twitter video. "I discovered the game that I love -- the game of football. Ever since then, I've given my life to the game. I love everything about it.
"... Football gave me everything I ever wanted and more. It taught me about hard work, dedication, teamwork. It took me to college and the NFL. It made me money and gave me a life most people could only dream about. I'm here today to make sure the world knows how much I still love football, how grateful I am for everything football gave me.
"And I'm here to let the world know that today I am officially retiring from the game I love so much."
The Steelers put Shazier -- the team's first-round pick in the 2014 NFL Draft -- on the reserve/retired list earlier this year -- an administrative move that kept him as a member of the franchise but signaled the end of his playing career.
"Never once have you ever said, 'Why me?'" Steelers general manager Kevin Colbert told Shazier during a video conference Wednesday. "And that gives us the strength and gives others the strength to know that any challenge you can overcome and you have overcome.
"... I just want you to know, you can retire from the game of football, but you're never going to retire from being a Pittsburgh Steeler."
Shazier, a two-time Pro Bowl selection, spent parts of four seasons (2014-17) with the Steelers. He finished his career with 299 total tackles, seven sacks, seven forced fumbles, three fumble recoveries, seven interceptions and 25 passes defensed.
During a game against the Cincinnati Bengals on Dec. 4, 2017, Shazier was left partially paralyzed after a tackle attempt on Bengals receiver Josh Malone. Shazier was rushed to a University of Cincinnati hospital and later underwent spinal stabilization surgery.
Shazier didn't regain movement in his legs until February 2018.
"To lose the game in a way I never envisioned has not been easy," Shazier said. "When you play the game of football the way I did, you convince yourself you're Superman, that nothing can stop you. But then the moment I got hurt, I stopped being Superman. That was difficult to make sense [of]."
Since then, Shazier has reached numerous milestones in his rehab process. He walked across the stage with the help of his now-wife, Michelle, at AT&T Stadium in Arlington, Texas, to announce the Steelers' first-round pick in the 2018 draft.
Shazier began jogging for the first time since his spinal surgery in November 2018, according to then-Steelers linebacker coach Joey Porter. In April 2019, Shazier posted a video of himself on social media doing a box jump.