Seattle Mariners v Arizona Diamondbacks

In This Photo: Michael Phelps
Olympic gold metalist swimmer Michael Phelps throws out the ceremonial first pitch prior to a game between the Arizona Diamondbacks and the Seattle Mariners at Chase Field on August 25, 2018 in Phoenix, Arizona. All players across MLB will wear nicknames on their backs as well as colorful, non-traditional uniforms featuring alternate designs inspired by youth-league uniforms during Players Weekend.
(Aug. 25, 2018 - Source: Norm Hall/Getty Images North America) more pics from this album »