Ratcliffe (upper body) was returned to AHL Chicago last Tuesday, according to the AHL transaction page.
Ratcliffe sustained an upper-body injury that will rule him out versus Chicago on Thursday, Lou Korac of NHL.com reports.
Ratcliffe signed a professional tryout agreement with the Blues on Thursday.
Ratcliffe was waived by the Flyers on Friday, Adam Kimelman of NHL.com reports.
Ratcliffe signed a one-year, two-way contract with the Flyers on Tuesday.
Ratcliffe was assigned to AHL Lehigh Valley on Thursday.
Ratcliffe was recalled from AHL Lehigh Valley to the active roster Tuesday.
Ratcliffe was demoted to AHL Lehigh Valley on Wednesday.
Ratcliffe was promoted from the taxi squad to the active roster Thursday, Jordan Hall of NBC Sports Philadelphia reports.
Ratcliffe was promoted to the Flyers' taxi squad Wednesday.