The Kansas City Royals have placed Zack Greinke on the injured list with a strained right forearm.
Greinke, 38, complained of tightness in his arm following Sunday's start against the Minnesota Twins.
He is 0-4 with 5.05 ERA this season.
"Any guy who has been around as long as he has, he kind of knows what he feels and knows what most likely will work," Mike Matheny said. "We're just trying to get ahead of it right now, just looks like it's going to take a little time."