"You hate to see a rainout, but we have a couple of guys who can probably use a day [off]," Giants manager Bruce Bochy said.
Second baseman Marco Scutaro, who had been stricken with flu-like symptoms, felt better after batting practice -- when it still seemed as if a game might be played -- and was able to rest instead of pushing himself to play.
Center fielder Angel Pagan, who hasn't played since last Saturday as he strives to recover from a strained left hamstring, probably won't play in Saturday's first game, but was rated as "50-50" by Bochy for the second game.
The opener of the doubleheader was set for 10:15 a.m. PT, followed by the regularly scheduled nightcap at 4:15 p.m.
The altered schedule won't change the Giants' pitching plans. Right-hander Matt Cain, who never bothered to warm up Friday, will pitch Saturday's first game, followed by left-hander Madison Bumgarner in the second game as previously slated.
Delaying Cain's outing by a day won't rob him of his usual rest, since Monday is a scheduled off-day.
"We can work around it," Bochy said.
Though Chad Gaudin remains virtually certain to leave the bullpen to start Sunday's series finale, Bochy continued to reserve the right to use the right-hander in relief if he's absolutely needed Saturday.
"If worse comes to worse, Gaudin is available," Bochy said.
The Giants last played a doubleheader on June 28, 2011, at Chicago's Wrigley Field. It was a productive day for San Francisco, which recorded a sweep by winning, 13-7 and 6-3.
Chris Haft is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.