Mets manager Jerry Manuel said the decision was precautionary because Santana has a history of feeling elbow soreness this time of the year. Santana remains on track to make his regular exhibition game debut Tuesday.
"I am not trying to do anything crazy out there," Santana said. "I am going to take a couple days and relax and get ready for Tuesday."
The left-hander said his elbow felt stiff after a bullpen session Wednesday, and he told pitching coach Dan Warthen he wanted to take some time off from throwing before preparing for his first game.
Santana had been slated to pitch one inning Friday, added to help Italy prepare for the World Baseball Classic. Mike Pelfrey will get the start against Italy.
"I try to keep my elbow loose, but especially early in spring training it takes a little bit of time," Santana said. "It takes time to adjust to everything and it takes time to get loose, but I don't think it's a big deal right now."
Santana, who had arthroscopic surgery Oct. 1 on torn cartilage in his left knee, didn't think the tightness in his elbow was related to rushing back from the knee surgery too soon but rather from overuse early in camp.
"I've been throwing bullpens here every other day, and I don't think I've ever done that in the past," Santana said. "The reason why is because we wanted to test my knee and make sure everything is fine, throwing every other day off the mound."
He threw off a mound for the first time since the offseason surgery on Feb. 10 and has faced no setbacks with the leg.
"My knee is fine," the two-time AL Cy Young Award winner said. "There's no problem, but it takes some time to get adjusted to pitching and throwing 100 percent off the mound, so right now I am just taking my time. There is no need to rush. My focus is on April 6."
Santana went 16-7 last year with a major league-best 2.53 ERA in his first season with the Mets.