Andre Ayew will be out for 10 days after injuring his left groin while on international duty.
The Marseille injured his groin during Ghana's Nations Cup qualifier at home to Swaziland last Friday.
Andre, 21, who was taken off in the second half of the 2-0 victory at home, missed the high-profile friendly with Brazil on Monday in London.
He will miss Saturday's Ligue 1 match at home to Rennes and next week's opening Champions League group match against Olympiakos in Athens.