Dyson, 28, has played in 18 games for the Royals this season, hitting .268 with a .286 on-base percentage. He has had some good pop this season, with eight of his 11 hits going for extra bases.
Lough, 27, has been hitting very well in Omaha this season with a .340/.393/.477 line in 36 games. He played 20 major league games last season, hitting .237 with a .292 OBP. Lough has played extensively at all three outfield positions.
The Royals depth chart currently lists Elliot Johnson as the only other back-up outfielder. However, Johnson is primarily an infielder and has played just seven games in the outfield in his major league career.