Cespedes had walked and struck out in two plate appearances before departing Game 4 of the National League Championship Series. The Mets won 8-3 to sweep the Cubs and advance to the World Series.
Amid the postgame celebration of the Mets' first NL pennant since 2000, Cespedes told reporters that his shoulder will not cause him to miss any of the World Series.
"I'll be fine by Sunday," Cespedes said. "If not, I'll chop it off and put a new [arm] on."
Mets manager Terry Collins said Cespedes had an injection in the shoulder and that he believes Cespedes will be fine by Friday's workout at Citi Field.
Cespedes was spotted golfing at suburban Medinah Country Club, which hosted the 2012 Ryder Cup, on Wednesday morning, according to an NBC 5 report.
Cespedes confirmed after the game that he played golf earlier in the day and said his shoulder was not injured during his round at Medinah.
A source told ESPN's Buster Olney that Cespedes irritated the AC joint of his shoulder while doing push-ups and that the Mets don't believe golf had anything to do with the injury, since Cespedes often golfs pregame.
Juan Lagares replaced Cespedes in center field and was hitless in two at-bats.
Cespedes is hitting .265 (9-for-34) with two homers and seven RBIs this postseason.
ESPN.com's Jon Greenberg contributed to this report.