MILWAUKEE—Pittsburgh Pirates starter Jeff Karstens was removed due to discomfort in his right hip flexor after getting only one out in the first inning against Milwaukee on Friday night.

The Brewers hit Karstens hard, with five of six batters reaching base. Aramis Ramirez hit a two-run single and Corey Hart hit a two-run homer to give Milwaukee a 4-0 lead. Jonathan Lucroy followed with a single on Karstens' 20th pitch, prompting trainers to go to the mound and talk to the right-hander.

He walked back into the dugout and was replaced by right-hander Kyle McPherson, recalled from Triple-A Indianapolis earlier Friday.

Karstens was pitching for the first time since being removed due to a grain strain after seven innings in a 4-0 victory over Milwaukee last Saturday.