Seven-time Pro Bowl linebacker Luke Kuechly, the NFL's most prolific tackler since being drafted by the Carolina Panthers in 2012, has announced he is to retire aged 28.
Kuechly, who has been the heart of the Carolina defense since the team selected him with the No 9 overall pick nearly eight years ago, stunned the NFL world by revealing his decision in an extended statement on the Panthers website.
"I think now is the right chance for me to move on," Kuechly said. "It makes me sad because I love playing this game, I've played it since I was a kid.
"It's my favourite thing in the world to do. The memories I have from this place and this organisation and being on the field with these guys - they'll never go away."
The former Boston College star immediately became a hit at middle linebacker with the Panthers, helping steer the team to three consecutive NFC South division titles from 2013-15.
The run culminated with the team's league-best 15-1 record and an NFC title in 2015, with the Panthers eventually losing to the Denver Broncos in Super Bowl 50.
Kuechly was a tackling savant upon his arrival into the league, leading the NFL with 164 tackles in his rookie season as he was named NFL Defensive Rookie of the Year.
He also topped all players in tackles two seasons later in 2014 with 153, and ends his career with more tackles than anyone since his 2012 season debut (1,092).
"While I wish we could have him for many more years, he has done everything the right way and we respect the decision that he's made," Panthers owner David Tepper said.
"Luke is a once-in-a-generation player and someone we want every member of this organisation to emulate."
Kuechly earned Pro Bowl selections in every season except his rookie campaign, and his five first-team All-Pro nods since 2012 ranked tied for first with Los Angeles Rams defensive tackle Aaron Donald, Seattle Seahawks linebacker Bobby Wagner and Houston Texans defensive end J.J. Watt.
In the Super Bowl era, only Hall of Famer Lawrence Taylor (seven) earned more first-team All-Pro selections in his first eight seasons than Kuechly, who in 2013 also became the first player since Taylor to win Defensive ROY honours and NFL Defensive Player of the Year honours in consecutive seasons.
While he started and played in 118 of a possible 128 regular-season games over his career, and missed just one game over the past three seasons, he was known to play through several injuries.
He missed six games in the 2016 season due to effects from a concussion.
"In my heart I know it's the right thing to do," he added
"There's only one way to play this game since I was a little kid - play fast, play physical and play strong. And at this point I don't know if I am able to do that anymore."
Kuechly joins a group of recent NFL stars to call it quits in recent years before turning 30, including former Indianapolis Colts quarterback Andrew Luck and ex-New England Patriots tight end Rob Gronkowski.
Players and coaches from around the NFL were quick to take to social media to congratulate Kuechly on his outstanding career.