Gabon were not allowed to field captain Pierre-Emerick Aubameyang who although out of COVID-19 isolation was not allowed to play by the Confederation of African Football.
“According to the CAF medical commission, the players Pierre-Emerick Aubameyang, Axel Meye and Mario Lemina, barely out of COVID isolation, cannot take part in this match.
“Medical examinations show cardiac lesions and CAF did not want to take any risks,” the Gabon Football Federation tweeted.
Ghana, who won the last of their Cup of Nations titles 40 years ago, had lost their opener to Morocco and needed victory to put themselves back in contention for a second round place.
They got off to a vibrant start as Ayew turned his marker and then hit a bullet to break the deadlock after 18 minutes.
Gabon are now second on four while Ghana remain on one and the Comoros have yet to get off the mark.
Gabon are not guaranteed a top-two finish but four points should be enough to ensure they reach the last 16, if not in the top two then as one of the four best third-placed finishers.