Onazi was on the verge of joining Birmingham but has failed to get work permit.
Onazi was on the verge of joining Birmingham from Turkish club Trabzonspor but failure to get a work permit in England has put the move in doubt.
After agreeing on personal terms and passing his medical head of the move, Onazi needed a work permit which will allow him to play professionally in England.
Despite playing the required number of international games, his application was rejected by the FA last week and an appeal was unsuccessful because of Nigeria’s position on the FIFA Ranking.
From the latest ranking, the Super Eagles of Nigeria are 38th in world football and 54th in aggregate over the past two years.
The poor aggregate score is as a result of the Super Eagles failure to qualify for the past two editions of the Africa Cup of Nations (AFCON) tournament.