Arizona Cardinals quarterback Carson Palmer has announced his retirement after 15 seasons in the NFL.
Palmer, 38, was selected by the Cincinnati Bengals with the first overall pick in the 2003 NFL Draft, having won the Heisman Trophy at USC.
He spent eight seasons at the Bengals and, after a short stint with the Oakland Raiders, he moved to Arizona in 2013 to play his final five seasons with the Cardinals.
Palmer finished his career with 46,247 total passing yards, 294 touchdown passes and 187 interceptions. He also bows out with a 62.5 completion percentage and an 87.9 passer rating.
"Over the years, I've had team-mates who decided to hang it up and I would ask them how they knew it was time to walk away. The answer was almost always the same: 'You just know.'" Palmer said in a letter published by the Cardinals.
"For me, that time is now. For 15 years I've been able to play quarterback in the NFL, and it's been the most incredible experience in my life. There wasn't one second that I took for granted or failed to appreciate what a tremendous privilege it is.
"What I'll never forget are the relationships - not just the amazing teammates and coaches, but all of those countless people at the Bengals, Raiders and Cardinals who work behind the scenes to make this whole thing run."
Palmer was reduced to just seven games this season after breaking his left arm and was placed on injured reserve with nine touchdowns and seven interceptions.
With the quarterback following head coach Bruce Arians into retirement, the Cardinals could be ready to usher in a new era. Veteran wide receiver Larry Fitzgerald has yet to announce his decision for next season, but the end of his career could be just around the corner as well.