Top row: Peyton Manning, Lionel Messi and Serena Williams. Bottom row: Patrick Mahomes, Naomi Osaka, Brittney Griner and Kevin Durant. THR Illustration; Ron Jenkins/Getty Images; Justin Ford/Getty Images; Dustin Satloff/Getty Images; Minas Panagiotakis/Getty Images; Christian Petersen/Getty Images; Michael Le Brecht/Disney/Getty Images Compared to only five years ago, managing an athlete's career has become a whole new game. Putting together THR's inaugural sports agent and manager list, of course, involved some consideration of the value of rich player contracts.