Marchan was recalled from Triple-A Lehigh Valley on Tuesday.
The 25-year-old was with the Phillies as the 27th man for the two-game series versus the Mets in London, and he's now fully on the big-league roster with J.T. Realmuto (knee) landing on the injured list. Marchan hasn't seen MLB action since 2021, but that will change the first time he operates as the backup to fill-in catcher Garrett Stubbs.