Vargas (12-3, 2.62), the American League leader in wins, is in the midst of the best season of his career. However, he ended the first half of the season by giving up a season-high three home runs and tying a season-high in runs allowed (six) against Seattle.
In 10 career starts against the Tigers, Vargas is 3-4 with a 5.37 ERA, but he hasn't faced them since 2014. Likewise, Zimmermann has not pitched against the Royals this season. In four career appearances -- three starts -- against Kansas City, Zimmermann is 2-0 with a 1.44 ERA.
Three things to know about this game
• Royals first baseman Eric Hosmer is 2-for-10 with four strikeouts in his career against Zimmermann.
• Tigers second baseman Ian Kinsler owns a .322 average (19-for-59) against Vargaswith seven doubles, two home runs and six RBIs. The 59 at-bats are Kinsler's fifth most against an active pitcher.
•With a 7-1 record and a 1.84 ERA at Kauffman Stadium this season, Vargas has the most wins and lowest ERA at home among qualifying pitchers in the AL.
Wilson Alexander is a reporter for MLB.com based in Kansas City.