Ayew, scorer of Ghana's first goal in Tuesday's 2-2 draw with Benin in the opening group game, faces uncertainty over his readiness for the match against the Indomitable Lions.
Manchester City attacker Agyepong, on the other hand, has no chance of making a second straight appearance at the championship, in Egypt following a premature 35th minute substitution in the first game due to a head injury.
"Black Stars captain Andre Dede Ayew and Thomas Agyepong sustained injuries during the Ghana-Benin opening game last Tuesday at the Ismaïlia Stadium," the Ghana Football Association have announced via their official website.
"Both players were substituted as a precautionary measure.
"Further medical test reveal that Agyepong will not be available for selection for the Cameroon game.
"However the medical team are monitoring Dede’s condition and will advise the technical team regarding his availability depending on how he responds to treatment."
Ayew, playing in his sixth Afcon, entered the history books on Tuesday as his goal put him top as Ghana's all-time top scorer at the tournament with nine goals.