Portsmouth have asked the Football League to convene an immediate emergency tribunal hearing as they mount a challenge to Kanu's claim for £3 million in back wages, saying it is invalid.
Administrator Trevor Birch told ESPN that resolving the situation with Kanu would not on its own be enough to save stricken Pompey from their August 10 closure deadline - he still has the situations of three other players to sort out, including Tal Ben Haim's £3 million claim.
Kanu has left Fratton Park but his claim remains a threat, and Birch told ESPN: "Our hope is that it is now dealt with swiftly by the Football League, and we have asked today for a quick hearing to be convened. Kanu served the club with a 14-day notice which expired toward the end of last week. He has now left the club and walked out, effectively, from the final year of his contract.
"But his claims for monies prior to his final year is the issue which we now need the Football League to resolve, and I have spoken to the League today. We obviously dispute the Kanu claim, and if we can show that we have a strong case that would persuade the potential new owners to move forward, even if Kanu lodged an appeal.
"But first we have to win that case, and we also need to resolve the issues with the three other remaining players. We are still talking, and each in their own way are difficult, but those talks are confidential. Last week was a good week as we reached agreement with two players and have only four players left now to sort out. So there is still a bit to do and we are running out of time."
Earlier, Birch told the Portsmouth Evening News that Luke Varney, David Norris, Greg Halford and Erik Huseklepp had all "effectively walked away from what they are owed".
He said: "There are substantial sums in there, but they have made compromises to leave the club with years left on their deals. They have also agreed for their deferrals to be paid over a certain period of time. It's a terrible time for everybody, but they have helped the club and I'm sure fans will thank them."
Meanwhile, Birch has warned that it could take Pompey almost 20 years to find their way back to the Football League if they were liquidated and started again much lower down the football pyramid.
He told ESPN a view gaining momentum that it might be better for the club to go bust and start again did not necessarily take into account how far they might have to fall.
"It took Aldershot 17 years to get back into the Football League, and that could happen to Pompey," he explained. "You don't know just how far down the pyramid they may be forced to drop, so it's not quite so clear-cut as going out of business and then starting afresh.
"You really don't know where you would end up in the footballing pyramid, and that is the frightening prospect if this club goes out of business in a couple of weeks.
"It might sound good to drop into the Conference then fight back quickly into the League, but the Conference might not be so keen. They won't just guarantee Pompey a place, because it would be like turkeys voting for Christmas with their clubs wanting to get into the League and not wanting a club like Pompey to take one of their places.
"It may well be that the Football League rules mean that Pompey would have to drop at least three leagues. So the best option is to save the club from going under, and that is what I am trying to do in the limited time we have left to do it."
Birch - who said that "while there is still a chance we shall not give up on Portsmouth" revealed to ESPN two weeks ago that the club would be shut down on August 10 if the issues surrounding remaining high earners were not resolved.