Marchant’s case was confirmed by lateral flow and PCR tests on Friday and he will miss at least the start of the training week at the squad’s base in Surrey.
The versatile Harlequins back, who covers outside centre and wing, was set to feature at Murrayfield on Saturday as England contend with a lengthy injury list.
It throws his participation in the Calcutta Cup clash into doubt, while prop Joe Marler also remains in self-isolation because of coronavirus.