Mustafi missed Sunday's 1-1 draw at Southampton with a thigh injury, and the German international has not recovered in time for the visit to the London Stadium.
Ramsey sustained a hamstring problem against the Saints, and Wenger has confirmed that the issue is severe enough to keep the midfielder out of the derby clash with the Hammers.
The Frenchman told reporters: "Mustafi will not be back. We lost Ramsey against Southampton. He will not be available for tomorrow's game.
"Everybody else apart from the long-term injuries will be available."
Arsenal head into the contest sitting in fifth place in the Premier League table.