KANSAS CITY -- Royals left-hander Danny Duffy will be skipped in the rotation on Saturday after discovering some stiffness in his shoulder while warming up for a bullpen session on Thursday.
"I was playing catch a couple of days ago and as I was getting out in front of my motion [the shoulder] felt a little stale," Duffy said. "And yesterday as I got through warming up, it just grabbed a little bit. Felt like I needed a little WD-40 in there."
Duffy's next start will be Tuesday at Yankee Stadium.
Right-hander Edinson Volquez will move up to take Duffy's spot on Saturday against the Cardinals, and right-hander Yordano Ventura will move up to take Sunday's start.