The Bay Area forecast, though, calls for a steady stream of showers throughout the day.
The Giants (4-2) had back-to-back rainouts for the first time in 45 years after Wednesday’s meeting was postponed more than three hours before the scheduled first pitch.
Giants right-hander Matt Morris had his start pushed back for the second straight day and third time this season.
Houston rookie right-hander Taylor Buchholz was expected to make his first career start during the series, but won’t pitch because of the schedule changes.
He was originally scheduled for Tuesday and then moved to Thursday before Wednesday’s postponement.
Bonds underwent three knee surgeries that caused him to miss all but 14 games last season.
“I’d like him to play even if the field isn’t 100 percent,” Alou said.
Bonds said: “My knee, it’s good.”
Bonds remains six homers shy of Babe Ruth’s 714 for second all-time. He is just 2-for-12 with four runs in five games this season.
This is the longest Bonds has gone into a season when healthy without a homer since 1998, when he didn’t hit one until San Francisco’s 13th game.
Morris, who played catch Wednesday and last had a bullpen session on Saturday, made his only appearance as a Giant on April 5. After signing as a free agent, Morris allowed one earned run and five hits in 6 1-3 innings in a road win against San Diego.
The last time Morris had this rest while healthy was when he had an eight-day layoff during the 2002 playoffs while pitching for the St. Louis Cardinals. Pitching in the National League Championship Series opener against the Giants, Morris allowed seven runs and 10 hits in 4 1-3 innings of a 9-6 loss at Busch Stadium.
“Extra rest leads you to believe you can do things you can’t,” Morris said. “That was a valuable lesson.”
Morris will face the Astros for the first time since taking a loss in Game 3 of last year’s NLCS.
There have been just five rainouts at the Giants’ waterfront ballpark since it opened in 2000 and 32 since the team moved from New York to San Francisco in 1958. The last time consecutive games had been rained out was April 21-22, 1961, against St. Louis.
The Astros (5-2) were scheduled to make their only trip to San Francisco this season, but will return to make up a game on May 8.
Backe enters after he allowed one run and three hits in six innings of a 6-1 home win Friday over Washington.
Cain took a no decision in his lone appearance, allowing four earned runs and seven hits in six innings of a 14-6 home loss to the Braves on Friday.
Oswalt, a 20-game winner each of the last two seasons, has lost his last three starts in San Francisco, allowing 13 runs and 27 hits in 15 2-3 innings.
Houston has dropped nine of its last 12 in San Francisco.