PORT ST. LUCIE — Johan Santana’s first Grapefruit League appearance of the spring will have to wait.

With the left-hander still trying to build up strength in his shoulder, Mets general manager Sandy Alderson said Friday that Santana has been scratched from his scheduled March 2 start against the Marlins. Santana now won’t pitch until somewhere in the March 10-15 range, according to Alderson.

Alderson said the Mets still have Santana penciled in for Opening Day on April 1 against the Padres at Citi Field, but says it’s possible he won’t be ready.

“There is no structural issue,” Alderson said. “It’s just a matter of building up strength, so he will be long-tossing before he gets back on the mound.”

Alderson said Santana is behind in his throwing program based on resting all winter, after getting shut down last August. The lefty is 2 1/2 years removed from surgery to repair a torn anterior capsule in his left shoulder.

mpuma@nypost.com