The Phillies optioned Thompson to Triple-A Lehigh Valley on Thursday.
Thompson lost his spot on the active roster after the Phillies acquired Aaron Loup from the Blue Jays and activated Adam Morgan from the paternity list. After working almost exclusively as a starter for the Phillies in 2017, Thompson has transitioned to a bullpen role this season but hasn't noticed a dramatic improvement in his results. Over nine appearances at the big-league level this season, Thompson has yielded nine earned runs on 14 hits and 11 walks over 16.1 innings.