The Royals' matchup with the Twins on Saturday has been postponed due to rain, Pete Grathoff of the Kansas City Star reports. The game will be made up as part of a doubleheader on July 1.
The Royals will simply push Hammel back a day, and he'll take the hill for Sunday's series finale. That means Danny Duffy will likely be on the mound for Monday's series-opener against the White Sox.