Pittsburgh Steelers linebacker Ryan Shazier announced his retirement from professional football on Wednesday, nearly three years after suffering a spine injury.

Shazier underwent spinal surgery after being injured in a game against the Cincinnati Bengals in December 2017 and has not played since.

"When I was 5 years old, I made the greatest discovery of my life," Shazier said in a video posted to Twitter. "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 ...

"I'm here today to make sure the world knows how much today I still love football. How grateful I am for everything that 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 28-year-old Shazier, a two-time Pro Bowler, chronicled his physical progress since the injury and has stayed with the Steelers, helping coach the linebackers.

Shazier was selected by the Steelers in the first round of the 2014 Draft out of Ohio State University.