His shoulder problems are just the latest in a long list for Waechter since he signed a $640,000 contract with the Royals as a free agent last winter. He had a split fingernail and blisters during Spring Training, followed by a sore elbow, an oblique strain and then the shoulder injury.
As a result, he pitched just 5 1/3 innings in five games for the Royals with no record and an 8.44 ERA.
Reliever Juan Cruz, on the disabled list with a right shoulder strain, is making progress and gaining arm strength.
"We don't have any projection as to exactly when he'll be back but we still expect him to pitch again this year," manager Trey Hillman said.
Cruz pitched in 43 games with a 3-4 record and 6.17 ERA before going on the disabled list on Aug. 6.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.