Schwimer joined the Phillies on Wednesday before the NL East leaders played the Arizona Diamondbacks. Polanco was placed on the DL after Tuesday night's loss. He has a sports hernia.
Schwimer was 9-1 with 10 saves and a 1.88 ERA in 46 appearances for Lehigh Valley and made the International League All-Star team. To make room for Schwimer on the 40-man roster, pitcher Joe Blanton was transferred to the 60-day DL.
Polanco is hitting .275 with four home runs and 40 RBIs in 89 games. He previously missed 19 games with a back injury.