Wearing a Washington Grays Negro Leagues throwback uniform, Washington Nationals starting pitcher Jordan Zimmermann throws during the first inning of a baseball game against the Kansas City Royals Saturday, Aug. 24, 2013, in Kansas City, Mo. (AP Photo/Charlie Riedel)

Photo by: Charlie Riedel

Wearing a Washington Grays Negro Leagues throwback uniform, Washington Nationals starting pitcher Jordan Zimmermann throws during the first inning of a baseball game against the Kansas City Royals Saturday, Aug. 24, 2013, in Kansas City, Mo. (AP Photo/Charlie Riedel)