The team says X-rays were negative and Cuddyer has a bruise.
Cuddyer was plunked Tuesday night by a 90 mph fastball from Phillies starter David Buchanan, the second batter he hit in the second inning. Wilmer Flores also was hit with a 90 mph fastball but remained in the game.
Cuddyer was replaced by pinch-runner Kirk Nieuwenhuis, who took over in left field and made an outstanding catch in the corner moments later.
Buchanan was booed loudly by the Citi Field crowd when he came up to bat in the third.
Cuddyer, hit with the next pitch after Lucas Duda's three-run double, had an RBI single in the first. He joined the Mets as a free agent in the offseason, signing a $21 million, two-year contract.