Guillen made comments about fans to a large media group on Friday when asked about being booed for jogging slowly to first base on a ground ball two days before. He was out despite a poor throw.
He made the apology through two reporters after Saturday night's 5-1 loss to St. Louis.
"You guys know how hard I work," Guillen said. "I'm just not the type of player to be running the way I was running. But it's over and I'm sorry if I hurt anybody with those comments about the fans."
Guillen's comments, with expletives bleeped out, had been played extensively over radio outlets in Kansas City.
"I understand a situation like this grabs a lot of attention with the fans," Guillen said.
Guillen said he apologized to Royals general manager Dayton Moore and through him to owner David Glass.
"Dayton didn't take it real well, and probably the owner didn't take it real well, but I just want to apologize for that," he said. "I should have just said it in a different way. If I hurt anybody, I'm sorry and it was just kind of in the heat of the moment right there."
In his Friday session with the media, Guillen insisted that he was playing with sore hips and groins and was not running hard at selected times to save his legs and to keep from going on the disabled list.
Moore backed Guillen's explanation about his legs, but apparently was not pleased with the way his $36-million player expressed himself.
"Dayton is my boss," Guillen said. "I don't want to make the guy look bad, because he paid me all this money to come here and he believes in me and I've got to make sure I represent myself much better."
Although he expected more booing from fans on Saturday night in the wake of his comments, Guillen was pleasantly surprised.
"They just started clapping and stuff," Guillen said, "and I was real happy with that."
Guillen reiterated that he was sorry.
"That's my apology to them. I don't want to offend anybody and, hopefully, we can move on from this," he said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.