Manager Jerry Manuel also gave third baseman David Wright and outfielder Gary Sheffield the day off, and said that injured starter Oliver Perez experienced a setback in his rehab and will be sent to the team's training facility in Florida on Sunday.
Perez, who signed a $36 million, three-year contract in the offseason, went on the DL on May 6 with inflammation in his right knee. He was expected to make a rehab start Sunday at Triple-A Buffalo, but an MRI exam on Thursday revealed patellar tendinitis.
Schneider was placed on the DL nearly six weeks ago because of a muscle strain in his back. He made his first start since April 15 and went 1 for 3 in the Mets' 7-3 loss.
"It was weird watching them on TV, you know?" Schneider said. "It's only the second time I've ever been on the disabled list."
The Mets have done all right without him, winning six of their last eight games and jockeying with Philadelphia for the early lead in the NL East. A big reason why has been Omir Santos, a 28-year-old rookie catcher who's provided an offensive spark for the banged-up Mets.
Santos homered and drove in the winning run in the 11th inning of a 2-1 victory over Florida on Friday night, less than a week after his two-run shot in the top of the ninth helped the Mets beat Boston. His play essentially forced the Mets to keep him around when Schneider was due to come off the disabled list, and the club wound up dealing Ramon Castro to the Chicago White Sox on Friday night to avoid having a glut of catchers.
Manuel said he expects Santos to be back in the lineup for the series finale against Florida, with Schneider starting the opener of a three-game set Monday at Pittsburgh.
Wright was given the day off Saturday for the first time this season. The Mets had hoped to give their struggling All-Star a day off during the Pittsburgh series, but changed their plans so that he wouldn't face Marlins ace Josh Johnson.
The big right-hander went seven innings and improved to 6-0 against the Mets.
"We knew it would come to a point where they would need a day off at some point. I felt like David, Sheff had played a lot," Manuel said. "Johnson has been tough on us, and I thought we'd throw something different against him."
The ailing Mets lost outfielder Carlos Beltran to a stomach virus late in the game, and the team said he was day to day. New York is already without injured regulars Ryan Church (hamstring), Carlos Delgado (right hip) and Jose Reyes (right calf).
Reyes took some swings in the indoor batting cage before the game and could head to Port St. Lucie, Fla., on Sunday to begin a rehab assignment. Reyes hasn't played since May 20.