Denver Broncos quarterback Peyton Manning is to announce his retirement on Monday, ending a sparkling 18-year career in the NFL.
Manning, who turns 40 later in March, played his last game when he helped the Broncos win the Super Bowl in February.
It was his second Super Bowl win, the first coming in 2007 during a 14-year spell with the Indianapolis Colts.
One of the game's most prolific passers, he was voted the NFL's most valuable player a record five times.
Manning will retire as the NFL's all-time leader in passing touchdowns (539), passing yards (71,940) and quarterback wins (186, tied with Brett Favre).
His teams made the play-offs in 15 of his 18 seasons.
Before the Super Bowl, the NFL began an investigation into allegations that banned substance human growth hormone was sent to Manning's house when he was recovering from neck surgery in 2011.
He has described the allegations, made by broadcaster Al Jazeera, as "complete garbage".
In defeating the Carolina Panthers in this year's Super Bowl 50, Manning became the oldest quarterback to win the showpiece event - and the first starting quarterback to win it with two different teams.
It had been rumoured the surprise 24-10 victory would be his last game, but he said afterwards he would "take time to reflect".
"When you look at everything Peyton has accomplished as a player and person, it's easy to see how fortunate we've been to have him on our team," said Broncos general manager John Elway, himself a two-time Super Bowl-winning quarterback.