NEW YORK — Yankees ace Chien-Ming Wang will be on crutches and wear a boot for at least six weeks after injuring his right foot running the bases, the latest blow to New York's banged-up pitching staff.

It was not certain when Wang would be able to pitch again. An examination in New York on Monday showed he partially tore a tendon and sprained his foot Sunday during the Yankees' 13-0 win at Houston.

Making a rare appearance on the bases during the interleague game at an NL park, Wang pulled up rounding third and hobbled home on Derek Jeter's single. Wang doubled over after scoring, pointed toward his right foot and was helped off the field.

"It's a manager's worst nightmare when a pitcher's on a basepath," manager Joe Girardi said after the victory. "It's unfortunate."

Wang will join injured Yankees starters Phil Hughes and Ian Kennedy on the disabled list.

Wang is 8-2 with a 4.07 ERA in 15 starts. The right-hander won 19 games in each of the last two seasons.

The Yankees were off Monday and start a series Tuesday night at home against San Diego. Their win in Houston kept them six games behind Boston in the AL East.

The sinkerballing Wang has been the most consistent Yankees starter over the last couple of years.

Mike Mussina and Andy Pettitte remain in the rotation, and Joba Chamberlain recently was converted from relieving to starting. Starter Darrell Rasner has been in a slump lately.

Wang was well on his way to helping the Yankees finish off a three-game sweep in Houston when he was hurt. He'd pitched five strong innings, and scored during an eight-run burst in the sixth inning that put New York ahead 11-0.

Wang is 5-0 in seven road starts this season.

After the game, Mussina summed up the problem that AL pitchers sometimes have playing at NL parks.

"We don't hit, we don't run the bases," Mussina said. "You get four or five at-bats a year at most, and if you happen to get on base once or twice, you never know. We run in straight lines most of the time. Turning corners, you just don't do that."