Thompson was recalled from Triple-A Lehigh Valley on Saturday.
Thompson has an ugly 7.27 ERA in 8.2 innings at the big-league level this season, though his 2.40 FIP indicates that there's been a lot of bad luck in that small sample. He's been uninspiring in 31.1 Triple-A innings, however, posting a 5.17 ERA. He and Yacksiel Rios will fill low-leverage roles in the Phillies' bullpen, with Mark Leiter being optioned and Luis Garcia (wrist) hitting the disabled list.