General manager Sandy Alderson announced the roster move prior to Sunday afternoon's game against the Washington Nationals.
Alderson said the team expects Paulino to return for the Washington series on Apr. 26.
"It's important for him to ramp it up these next 15 days so he can help us," Alderson said. "He'll initially help us in a backup role."
Paulino, who had been battling anemia, was serving a 50-game suspension for testing positive for a banned substance, which he ingested inadvertently.
It finally ended on Saturday, so the Mets had to make a move before Sunday afternoon's game.
As for Paulino's condition, Alderson said: "His blood count is up to an acceptable level. Far higher than it was at the time of his physical."
Alderson said that reliever Jason Isringhausen is continuing his 15-day extended spring training program in Port St. Lucie, Fla.
"His promotion is on-going consideration," Alderson said.
Alderson added that the team has considered adding a reliever the last few days.
He also noted that left fielder Jason Bay continues to be pain free.
Mike Mazzeo is a regular contributor to ESPNNewYork.com.