Chiefs' Patrick Mahomes: Mega-extension confirmed

The Chiefs have confirmed that Mahomes has been signed to a 10-year extension that is slated to keep the QB with the franchise for the next 12 seasons.

Per ESPN.com, Mahomes' extension is reportedly worth $450 million, while the injury guarantee in his deal is $140 million. Meanwhile, Ian Rapoport of NFL Network suggests that the pact is worth $503 million, with the star signal-caller getting $477 million "in guarantee mechanisms as well as "outs" if the guarantee mechanisms aren't exercised." Either way, Mahomes, who turns 25 in September, is now in line to have the largest contract in American professional sports.