HOUSTON — Chien-Ming Wang left the Yankees’ clubhouse on crutches yesterday after spraining his right foot running the bases in New York’s 13-0 win over the Houston Astros.

The Yankees’ ace will have an MRI exam in New York today and not even Wang could gauge the severity of the injury yet. He was wearing a soft cast after the game.

“I feel sore,” Wang said through a Yankees spokesman. “Of course I’m disappointed. On Tuesday, when I know more, I will talk then.”

After pitching five scoreless innings, Wang (8-2) pulled up as he rounded third on Derek Jeter’s two-run single during the Yankees’ eight-run sixth. He hopped the rest of the way home and pointed to his right foot after scoring.

A trainer rushed from the dugout to check on him and Wang was helped off the field. He was relieved in the sixth inning by Ross Ohlendorf.

Getting a rare chance to hit against an NL team, Wang had reached base on a bunt that turned into a fielder’s choice.

Mike Mussina, who won Saturday’s game, talked to Wang after he was hurt.

“We don’t know how bad it is,” Mussina said. “We’ll wait and see. Before we put him out for a month or two months, let’s wait and find out how it looks. We’ll find out tomorrow or the next day.”

Wang still earned his second straight win after taking a loss or no-decision in the previous six starts. He’s 5-0 in seven road starts this season and may miss time just as the Yankees moved four games over .500 for the first time this season.

“You wish for the best,” Jeter said. “It’s one of those things that you wish wouldn’t happen, but if he’s out for a while, we’re going to have guys step in and fill that void.”

Yankees manager Joe Girardi said he would be “shocked” if Wang made his next scheduled start, against Cincinnati on Saturday. But Girardi also wouldn’t speculate on how serious the injury might be.

“We’ll have the tests tomorrow and then decide what the best plan of action is,” Girardi said. “You’re going to go through injuries. Clubs are going to go through injuries and you’ve got to find a way to get it done.”

Alex Rodriguez hit a three-run homer, his 185th as a Yankee, later in the New York sixth, tying Paul O’Neill for 16th on the franchise’s all-time list. Rodriguez reached 1,540 RBIs on the home run, passing Joe DiMaggio and tying Willie Stargell for 40th all-time.

Roy Oswalt (5-7) gave up seven runs on eight hits and matched season highs in walks (four) and pitches (117).

The Astros have lost nine of 11 and dropped five straight home games for the first time since August 2006. Houston was swept for the second time this season and has lost six consecutive series.

“I just know we’re playing bad and we’ve got to get better,” Oswalt said. “The entire staff, we all need to step it up. I’m as much to blame as anyone.”