Frazier has missed the Mets' past 24 games with a strained left hamstring. He is batting cleanup Tuesday night against the Baltimore Orioles for a Mets offense that is coming off a four-game sweep to the Chicago Cubs. New York scored just six runs during the series.
Frazier is hitting .237 with 5 home runs and 21 RBIs this season. He hit .444 in three minor league rehab games.
The Mets' offense, which has also been without injured slugger Yoenis Cespedes, has scored just 230 runs this season, ranked 27th in the majors.
Swarzak went on the DL on April 3 after straining a muscle on his left side during a game against the St. Louis Cardinals, just his second appearance with the Mets this season. He has a 3.86 ERA in 2 1/3 innings this season.
The veteran right-hander will be expected to shore up a shaky Mets bullpen, which is currently tied for the major league lead with 12 blown saves.