The Premier League pair were forced into self-isolation last week after returning positive tests upon reporting for international duty.
That meant both players missed out on involvement back-to-back wins over Togo in qualifying for the Africa Cup of Nations.
And they now look set to also miss games for their clubs this weekend - and possibly beyond - as they continued to self isolate in Egypt.
Liverpool face top-of-the-table Leicester City at Anfield on Sunday before a Champions League meeting with Atalanta that could see them through to the knockout stages.
Arsenal, meanwhile, face a tricky trip to Leeds United ahead of a visit to Molde in the Europa League group stages.
Both Salah and Elneny will be unable to return to England until the provide a negative Covid-19 test.