Quarterback Carson Palmer called it quits Tuesday after 15 seasons in the NFL.
The Arizona Cardinals shared Palmer's open letter announcing his retirement in which he said he will "never forget" the relationships he developed and will "especially miss the grind" that came with playing football at the highest level for so long:
Palmer entered the league in 2003 when the Cincinnati Bengals drafted him with the No. 1 overall pick out of USC. He looked like a franchise quarterback in the Queen City at times, throwing for more than 3,000 yards in five different seasons and leading the team to the playoffs twice.