The Royals have placed All-Star catcher Salvador Perez, right-hander Nate Karns and two others on the disabled list in a series of roster moves ahead of their opener against the White Sox.
Infielder Adalberto Mondesi and outfielder Bubba Starling also went on the DL on Thursday, while veteran pitcher Wily Peralta and top prospect Ryan Zimmer were designated for assignment.
The moves created space for the Royals to select the contracts of right-hander Blaine Boyer and infielder Ryan Goins, and recall catcher Cam Gallagher from Triple-A Omaha.
Perez is expected to miss up to six weeks after hurting his knee Tuesday night while carrying luggage in his house. Karns has elbow inflammation, Mondesi has a right shoulder impingement and Starling has a left oblique strain.