PHILADELPHIA — He arrived, found his locker and slipped on his uniform, the one with the last name stretched tightly across his shoulders and around his number like a horseshoe. The clubhouse was quiet, but Noah Syndergaard was early, eager to begin his big-league career as soon as possible.

His first major league start is not scheduled until Tuesday. But here he was, stretching with the pitchers, signing autographs and shagging fly balls during batting practice before the Mets faced the Philadelphia Phillies on Saturday night.

The front office thought it prudent to call him up a few days in advance. He needed to acclimate. He needed to see what it was like, because they expect him to be here awhile.

So Syndergaard, the Mets’ top pitching prospect, got the call Friday afternoon in El Paso, where the Class AAA Las Vegas 51s were playing. Dillon Gee was headed to the disabled list, and Syndergaard was told to visit Wally Backman in the visiting manager’s office.