Ghana forward Andre Ayew suffered an injury on West Ham United 3-0 loss to Manchester City in their last pre-season friendly game in Iceland on Friday.
The 27-year-old winger started the game before being substituted in the 86th minute after he felt discomfort in his left leg.
Goals from Kevin de Bryune, Sergio Aguero and Raheem Sterling won the game for Manchester City.
The result leaves the London club with plenty of work to do before heading to Old Trafford on next Monday in the opening fixture of the English Premier League.