So Duffy went out for the fifth, keeping switch-hitter Dioner Navarro batting right-handed. Two pitches in, Duffy got Navarro to fly out. After that, the Royals called for the bullpen, but Duffy had more than done his part.
With Kris Medlen and Chris Young on the disabled list, Duffy was moved into the rotation on short notice. In his second start of the season, he started the conversation about whether he should stay there.
"We just know that we can't go wrong either way," Yost said about having Duffy in the rotation or the bullpen.
Duffy wasn't the only Royals pitcher who proved something Saturday.
Peter Moylan backed up the notion he has found a grove after a rough spring. Joakim Soria again indicated he is reliable after a tough start. And Wade Davis reiterated what everyone already knows.
The combined result was a stellar pitching performance that helped the Royals take their second straight game from the White Sox.
"[Moylan and Soria] were awesome," Duffy said. "Moylan came in and did his thing, and Soria got us out of a huge jam."
Moylan relieved Duffy in the fifth and came back for the sixth. He yielded two baserunners in the inning, but neither scored. Since being called up May 12, Moylan has not allowed a run in three innings of work.
The seventh was trickier. Chicago loaded the bases against left-hander Brian Flynn after Mike Moustakas misplayed an Eaton bunt with two runners on. Yost brought in Soria, who got Jose Abreu to ground into a double play. Despite a run scoring, Soria followed by getting Todd Frazier to roll over a 3-2 changeup, thus ending the inning and limiting the damage.
With Luke Hochevar and Kelvin Herrera unavailable, Soria went back out for the eighth, and he sent the White Sox down in order. It was the first time Soria has thrown two innings since 2011.
In the ninth, Davis came in, and despite walking Tyler Saladino, the closer threw another scoreless inning to get his 11th save of the season.
"It means a lot," Soria said. "It means we have a complete team, and we don't rely on just one guy. We can go early in the bullpen and we have plenty of guys there to perform."
And like that, the Royals did what they do best -- using depth and finesse to work a win against their division rivals.
"I think we've found something," Duffy said. "Our identity is just grinding out at-bats and trying to do everything we can to just get the ball to Herrera, Soria and Wade."
Cody Stavenhagen is a reporter for MLB.com based in Chicago. This story was not subject to the approval of Major League Baseball or its clubs.