An NFL superstar quarterback has been chosen for the annual honor of calling "Riders up!" at this year's Kentucky Derby in Louisville. Two-time Super Bowl-winning Kansas City Chiefs quarterback Patrick Mahomes will be in the paddock Saturday evening to signal riders to mount their horses. For Mahomes, this will follow a night of him partying at the Barnstable Brown Derby Eve Gala.Mahomes was just announced as a guest on Monday for Louisville's most exclusive Derby party, along with fellow NFL quarterback Aaron Rodgers and Hall of Fame NFL quarterback Peyton Manning.You can see the complete guest list for the party here.Louisville's Jack Harlow will be there, as well. The Grammy-nominate rap star had the honor of giving the "Riders up!" call last year.This year's Derby is May 6.