"I just made a late managerial decision to not play him," manager Trey Hillman said after the Royals' 6-3 victory.
Asked if Guillen was injured, Hillman merely repeated that statement and added, "The rest of it will stay in-house, for me at least. I just decided it was best not to play him."
Guillen had left the clubhouse by the time reporters entered after the game. However, the Kansas City Star reported reaching Guillen by phone and quoted him as saying: "I was not feeling good. I was sick." Guillen said he had a fever and was feeling weak before the game. He said he went home and took plenty of liquids, hoping to feel better.
Hillman juggled his original lineup, dropping Mike Aviles into Guillen's No. 3 slot. He shifted his outfield around and Mitch Maier was added to the lineup in center.
Guillen has been a hot hitter with a 13-game hitting streak in which he's 23-for-55, .418.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.