The Mets expect to go with Claudio Vargas (pictured) in Game 2 of Tuesday’s doubleheader in Atlanta, with Mike Pelfrey to follow as the starter Wednesday. John Maine still is scheduled to start Game 1 of the twinbill. Vargas, you’ll recall, is coming off a terrific Met debut last Wednesday, giving up just three hits in 6 1/3 innings in a hard-luck loss to the Nationals.