Portsmouth are ready to fight Nigeria's bid to take strikers Kanu and John Utaka two weeks early for next month's African Nations Cup.
Kanu and Utaka, Ghana's Sulley Muntari and Senegal's Papa Bouba Diop, will have to leave Pompey for the African Nations which runs from January 20 and could miss up to five domestic games depending on the progress of their countries.
But Nigeria boss Berti Vogts, the former German World Cup star and ex-Scotland manager, wants his squad to report early to attend a 14-day training camp ahead of the tournament in Ghana.
That would take Kanu and Utaka out of two extra Pompey matches and there are fears other nations could follow suit.
But Fratton Park chief executive Peter Storrie has vowed to try to hold back Portsmouth's African contingent as long as possible.
Storrie told the Portsmouth News: 'We will be protesting strongly and will be discussing it with the nations concerned.'
Storrie, who is confident he can win an appeal, added: 'It is just ridiculous. We all know who the countries in the quarter-finals will be. What do they need a 14-day warm-up for?
'We do not have to release them (early). There are FIFA rules which legislate for this. It is totally crazy.'
With reserve defender Djimi Traore also likely to be called up by Mali, manager Harry Redknapp added: 'I think I could lose five players to the African Nations Cup.
'That will leave me with a squad of just 14 players capable of playing at Premier League level and if we get an injury we are in trouble.
'I knew when I signed them they could be missing for a while in January and February but I still think it was worth the gamble to put us where we are with 27 points at this stage of the season.
'But I am going to have to get in three or four more players (in the January transfer window) to fill up the squad - maybe loans or somebody from the lower divisions if I can find them.'
Last month, Redknapp refused to release Kanu and Utaka for Nigeria's friendly against Australia at Fulham - on a day when there were no Premier League matches - after they picked up injuries against Manchester City.
Two years ago, Pompey persuaded Zimbabwe to let newly-signed Benjani Mwaruwari delay his African Nations Cup attendance to feature in their fight against relegation.
The £4.4million striker, now the Premier League's top scorer, eventually reported five days before the tournament started and even returned by private jet to play against Liverpool, less than 24 hours after a Zimbabwe game.
Pompey's current African Cup contingent are so far pencilled in to miss the Fratton Park clashes with Derby on January 19 and Chelsea on February 2.
They could also miss trips to Manchester United (January 30) and Bolton (February 9), as well as a potential FA Cup fourth-round tie on January 26.
But Benjani will be available after Zimbabwe failed to qualify for the finals.