Delgado missed his fifth straight game Friday night with a sore right hip after hurting himself sliding last month.
Delgado, who's batting .298 with four homers and 23 RBIs, missed five starts after the injury on April 26, but returned for seven straight games before missing the Mets' series with Atlanta earlier this week. The 36-year-old star hasn't felt much better while resting the injury and getting treatmen.
Outfielder Jeremy Reed took Delgado's place at first base against San Francisco's Tim Lincecum. Reed has played first base for just one inning as a professional, but Mets third base coach Razor Shines vouched for his infield skills to Manuel, who chose Reed's left-handed bat over Fernando Tatis against the Giants' NL Cy Young Award winner.
"I want to see what Reed can do at first base," Mets manager Jerry Manuel said. "I also at some point [on their 10-game road trip] want to see what [outfielder Daniel] Murphy can do. We've got to have flexibility."
The Mets also kept Jose Reyes out of the starting lineup for one more day with a stiff right calf. Reyes lobbied Manuel to play, but the manager elected caution with his shortstop, who's been under heavy criticism back home for his baserunning misadventures.
"We just want to wait one more day and see how it feels to be ready for tomorrow," said Reyes, batting .286 with 15 RBIs and 11 stolen bases. "It feels a little bit better. It's still sore, though. Jerry didn't want to take that chance and put me on the field. It's tough. I like to be the guy that's out there on the field."
Alex Cora was back in the leadoff spot and at shortstop for New York. The Mets set a franchise record with seven stolen bases in Friday's win over the Giants while Reyes sat out.
Manuel also said right-hander Tim Redding probably will come off the disabled list to start Monday's game against the Los Angeles Dodgers. Redding, signed from Washington as a free agent in the offseason, has been out since early in spring training with a right shoulder injury.
Right-handed reliever J.J. Putz should be available for Saturday's game after throwing on the side. He had a cortisone shot Thursday in New York to calm inflammation in his right elbow.
The Associated Press contributed to this report.