Riyad Mahrez was at the centre of a drug riddle as he missed the Community Shield in bizarre circumstances.
The Algerian, 28, had been keen to play at Wembley — but was pulled out by Pep Guardiola after revealing he had taken medication for an eye problem.
City feared Mahrez would fail a drug test, so decided not to take any risks with the £60 million ace.
Boss Guardiola said: “Riyad took some medicine, just a little bit, but we don’t know what he took and therefore doping control was a risk.
“The doctors did not know what was in the medicine.
So that’s why he did not play.
We could not take a risk because the doctors didn’t have the medicines or exactly what happened — and we did not want to risk it. Hopefully at West Ham on Saturday he will be fine.”