Ghana lost to the Gambia in their final group to qualify as the third-best team in Group C behind Morocco and Gambia.
Coach Karim Zito and his players face a strong Cameroonian side who are unbeaten in this competition.
Cameroon topped Group A with nine points and come up against a struggling Ghanaian side on Thursday.
Agyeman-Badu, who was part of Ghana's U-20 AFCON and World Cup-winning squad in 2009 said, the current team together with the coach must work hard to beat Cameroon in Thursday's game at the Stade Olympique de Nouakchott.
"Coach Karim Zito has a lot of work to do today against Cameroon looking at how poorly the team performed against the Gambians”, Agyeman-Badu said.
“But one thing that will work for Ghana in today’s game is the name the Cameroonians are bringing on board. Ghana always performs well against the big guns but found wanting against the so-called minnows.”
“Difficult game today, but Ghana can win,” he added.