"I just kept the guys loose before the game," Duffy said. "I wanted to get them laughing. I walked into the dugout and said, 'I need the vibe tribe tonight, guys.' Couldn't be happier with the result."
The result was a tidy 5-1 win, led by Duffy's seven shutout innings, that helped the Royals avoid the sweep.
"I just thought he did a tremendous job, seven strong innings in a game we really needed to win," manager Ned Yost said. "We didn't want to leave here getting swept, especially after playing good against Baltimore [last weekend]. Danny set the tone for us."
Duffy gave up three hits, walked two and struck out a season-high 10. He admitted afterward that he thought he had no-hit stuff.
"Everything had the action I wanted," he said. "Felt good from the get-go. I knew this was a game we really needed to have. I really wanted to excel for the boys."
Duffy's slider was spot on, and he struck out five of the first six Yankees he faced.
"I think I just got through [the slider] more," he said. "I think I just located the slider really well. I felt really good about my whole repertoire.
"I think we found something in the bullpen and in the side sessions between starts. You have to make adjustments on the fly in this game. I just did my job tonight, and the team did its thing."
Duffy didn't allow a hit until Jacoby Ellsbury led off the fourth with a bunt single. Ellsbury was originally was ruled out, but the Yankees challenged the call and won. Duffy's throw to first was in time, but first baseman Eric Hosmer pulled his foot off the bag, according to replay officials.
"I expect to make that play," Duffy said. "I pulled Hoz off the bag a bit. We practice that in spring all the time. I knew Jacoby was a burner, so I needed to get it over there quick.
"But overall, I'll take this. We needed it. It was a team win."
Jeffrey Flanagan has covered the Royals since 1991, and for MLB.com since 2015. Follow him on Twitter @FlannyMLB. This story was not subject to the approval of Major League Baseball or its clubs.