Portsmouth say Nigeria's plans to take Kanu and John Utaka early for the African Nations Cup are 'totally crazy'.
Kanu and Utaka, Ghana's Sulley Muntari and Senegal's Papa Bouba Diop will all be leaving Fratton Park to compete in the tournament from 20th January -ruling them out of games against Derby and Chelsea.
But Nigeria boss Berti Vogts wants his squad to report early to attend a 14-day training camp ahead of the tournament in Ghana.
That could result in Kanu and Utaka missing two extra matches, severely depleting Harry Redknapp's squad at a crucial stage of the Premier League season.
But Pompey chief executive Peter Storrie says the club intend to fight the move and have no intention to release players early.
"We will be protesting strongly and will be discussing it with the nations concerned," Storrie told the Portsmouth News.
"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."
To add to Redknapp's concerns Djimi Traore is also likely to be called up by Mali.
The Portsmouth boss 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."
Apart from the games with Derby and Chelsea, Pompey's African players could also miss trips to Manchester United (30th January) and Bolton (9th February), as well as a potential FA Cup fourth-round tie on 26th January.