Portsmouth striker Ayegbeni Yakubu has turned down a place in Nigeria's squad for two friendly matches in May. Yakubu was sent home from the African Nations Cup in January after being accused of breaking a curfew and turned down a subsequent invitation to return.
A club spokesman said: "Yakubu still feels he was harshly treated during the African Nations Cup."
Nigeria will play the Republic of Ireland and Jamaica in the Unity Cup in London on 29-31 May.
Yakubu has been in scintillating form since his return from the African Nations Cup and scored some crucial goals in Portsmouth's escape from relegation.