Nigeria coach Christian Chukwu tonight insisted that Jay-Jay Okocha and Kanu must report for African Nations Cup duty on Monday at the latest.
That revelation will come as a shock to Bolton and Arsenal who were hoping to hold on to the players for at least another week.
Should those clubs, and others, resist, then Chukwu says he would have no option but to report them to FIFA.
Arsenal want Kanu to remain as Dennis Bergkamp and Sylvain Wiltord are both injured but there will be no exceptions to the rule.
The tournament is due to start in Tunisia on January 24 and Nigeria are one of the seeded nations.
Chukwu is prepared to take a tough stance so he can get his best players on board when they announce their 22-man squad on Monday.
"The rules state that the players must be released to us 14 days before the tournament starts. We don't have a problem with that," he told the Press Association from their Portuguese training camp.
"Because of that rule, we don't want the managers in England to hold back the players any more.
Bolton were hoping that Okocha would be available to face Tranmere in the FA Cup on Tuesday and Portsmouth next Saturday.
But he will now have to report to the training camp on Monday as well as Kanu and Everton's Joseph Yobo.
Nigeria are scheduled to leave their training camp at the end of next week to set up another one in Tunisia, where they will complete their final preparations.