CHICAGO -- Freezing rain and snowy conditions in Chicago on Wednesday made it impossible for the Astros and Cubs to play their series finale at Wrigley Field, and the teams were waiting for Major League Baseball to approve a makeup date and time.

The Astros will stay on schedule pitching-wise. Wednesday's starter, Wandy Rodriguez, will be skipped this time through the rotation, so that Roy Oswalt can make his originally scheduled start in the opener in Philadelphia on Friday. Oswalt will be followed by Jason Jennings and Woody Williams.

Rodriguez will open the short two-game homestand with the Marlins on Monday, followed by Chris Sampson on Tuesday.

"I'm not going to bump Roy," manager Phil Garner said. "That's just what has to happen in Wandy's case."

The Astros had checked out of their hotel and arrived to the clubhouse around 10:30 a.m. CT on Wednesday morning, after the game was already cancelled. A few players worked out, while others played cards and watched television in the cramped visitors' clubhouse at Wrigley Field. They were hoping to head to the airport around 2 p.m. CT.

The Astros will have an off-day in Philadelphia on Thursday before the series with the Phillies. The forecast for the weekend isn't much better, although the Astros should have decent weather for Friday's game. The outlook for Saturday and Sunday looks bleak, with more rain showers ahead.