Manager Terry Collins said Friday that Cespedes will be the team's 26th man. He will bat third and play left field in the first game against the Braves, and could be available to pinch-hit in the second game.
"I've got a long routine, which usually takes me about an hour to get through, so I think it's going to help me stay healthy," Cespedes said through an interpreter Saturday. "They are waist, back, leg exercises. I think that my elasticity will improve."
The slugger played one game for Class A St. Lucie on Thursday. He went on the DL on April 28 with a strained left hamstring and then took a break of nearly two weeks after he had tightness in his right quadriceps.
Collins said the decision to call up Cespedes was based on "the fact he came out of the game fine with no issues" on Thursday.
"He accumulated a lot of at-bats even though he hadn't been in games," Collins said. "We think he's ready."
Asked how much Cespedes was missed, Collins said, "He's one of the best players in baseball. He's hard to replace. We've been very, very fortunate that the young man who replaced him played so well."
Michael Conforto has hit .303 with 14 homers and 36 RBIs, providing the production that had been expected from Cespedes.
"We'll flip-flop and move guys around and get everybody some playing time," Collins said, adding that Cespedes won't immediately assume a full-time role.
"Right now we'll be a little careful with Cespedes," he said. "We have to work him back in."
Cespedes hit .280 with 31 homers and 86 RBIs in 2016. He hit six homers in 18 games before his injury this year.