Patrick Mahomes has agreed a 10-year contract with Super Bowl champions the Kansas City Chiefs which will reportedly make him the highest-paid athlete in the world.
The quarterback's new deal is said to be worth up to 503million US dollars (£402.9m).
According to the official NFL website, Mahomes becomes the first athlete with a half-billion-dollar contract and the first American football player to be the highest-paid athlete in the sports world.
The 24-year-old was the youngest player to be named Super Bowl MVP when he led the Chiefs to their first NFL championship in 50 years with a comeback victory over the San Francisco 49ers in February.
Chiefs chairman and CEO Clark Hunt said in a statement: "Since he joined the Chiefs just a few years ago, Patrick has developed into one of the most prolific athletes in all of sports.
"With his dynamic play and infectious personality, he is one of the most recognised and beloved figures to put on the Chiefs uniform.
"He's an extraordinary leader and a credit to the Kansas City community, and I'm delighted that he will be a member of the Chiefs for many years to come."
Mahomes, who tweeted a video with the caption "Here to stay", originally entered the NFL as the 10th overall pick in the first round of the 2017 NFL Draft by the Chiefs.
He has started 31 games in three NFL seasons with the franchise, throwing for 9,412 yards with 76 touchdowns and 18 interceptions in the regular season.
Mahomes' deal passes baseball's Mike Trout as the largest one in sport after the Los Angeles Angels player signed a 12-year-contract said to be worth up 426.5million US dollars in March 2019.