Royals pitcher Ian Kennedy was diagnosed with a right medial hamstring strain Thursday after exiting a start against the Chicago White Sox in the top of the fifth inning at Kauffman Stadium.
Kennedy will be re-evaluated on Friday, a Royals official said.
Before departing, Kennedy allowed four earned runs in 4 1/3 innings. The Royals trailed the White Sox 5-0 as the training staff came out to check on Kennedy in the fifth. After a few moments, Kennedy walked to the dugout and left-hander Mike Minor replaced him.
Kennedy has a history of hamstring issues. He missed time in April 2015 because of a hamstring strain. He also experienced tightness in his hamstring near the end of spring training in 2016.