Mets manager Terry Collins said on Friday that Cespedes was "expected" to be activated from the disabled list to serve as the 26th man on Saturday, via James Wagner of the New York Times.
Cespedes' return comes after he was able to play all nine innings during a rehab game with the High-A St. Lucie Mets on Thursday, going 0-for-4.
The two-time All-Star was placed on the DL after he strained his hamstring legging out a double during an April 27 game against the Braves. It was his second hamstring injury in a week.
In 18 games this season, Cespedes is hitting .270/.373/.619. His six home runs are tied for fifth-most on the team.
The Mets need a spark to turn their season around. They enter play on Friday with a 25-33 record, 12 games behind the Washington Nationals in the National League East.