Houston Astros ace Roy Oswalt left Sunday's game against the Pittsburgh Pirates after four innings due to a left ankle contusion.
Oswalt, who was attempting to tie the franchise record for career victories in the outing, was struck in the foot by a sharply hit ground ball by Pedro Alvarez in the second inning.
He had a streak of 17 1-3 scoreless innings before that but retired only seven of the ensuing 14 batters he faced, allowing two runs on seven hits with five strikeouts.
Oswalt earlier this season requested a trade from the Astros and potentially has only two more starts prior to the July 31 non-waiver trade deadline. He is 143-80 in his career; Joe Niekro is the Astros' all-time wins leader with 144.