Having initially named a 28-man selection, Volker Finke has since seen his side play three friendlies against Macedonia, Paraguay and Germany.
They resulted in a win, a loss and a draw respectively and have allowed Finke to make his final decisions on the squad, with 34-year-old Idrissou among those to miss out.
Idrissou, who signed for Maccabi Haifa from Kaiserslautern in May, missed a penalty in the defeat to Paraguay and is not included in their list of forwards.
Strike Pierre Webo is named, despite initial fears over a shoulder injury picked up against Macedonia, while defensive pair Gaetan Bong and Jean-Armel Kana-Biyik will also not travel, the latter missing the chance to emulate his father Andre, who played at the 1990 and 1994 editions.
Guingamp goalkeeper Guy N'dy Assembe and Osasuna midfielder Raoul Loe are not named with Loic Feidjou and Cedric Djeugoue the only domestic players listed.
Goalkeeper Feidjou, alongside Sammy Ndjock, will serve as competition for Charles Itandje while Cotonsport team-mate Djeugoue was in good form against Germany on Sunday.
Finke's men get their campaign under way against Mexico in Group A on June 13.
Squad in full:
Goalkeepers: Loic Feudjou (Coton Sport), Charles Itandje (Konyaspor), Sammy N'Djock (Fethiyespor)
Defenders: Benoit Assou-Ekotto (QPR), Henri Bedimo (Lyon), Aurelien Chedjou (Galatasaray), Cedric Djeugou (Coton Sport), Nicolas N'Koulou (Marseille), Dany Nounkeu (Besiktas), Allan Nyom (Granada)
Midfielders: Eyong Enoh (Antalyaspor), Jean Makoun (Rennes), Joel Matip (Schalke), Stephane Mbia (Sevilla), Landry N'Guemo (Bordeaux), Edgar Salli (Lens), Alex Song (Barcelona)
Strikers: Vincent Aboubakar (Lorient), Eric Maxim Choupo-Moting (Mainz), Samuel Eto'o (Chelsea), Benjamin Moukandjo (Nancy), Fabrice Olinga (Zulte Waregem), Pierre Webo (Fenerbahce)
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