Pittsburgh Pirates pitcher Jeff Karstens left Friday's game against the Milwaukee Brewers in the first inning with a right hip flexor strain.

Karstens, who has battled a strained left groin, gave up four runs on five hits, including a two-run home run by Corey Hart, while only recording one out.

Karstens is 5-3 with a 3.47 earned run average in 14 starts for the Pirates this season. The right-hander missed much of the first half of the season due to shoulder inflammation.