A player who does not belong to either club could emerge this afternoon as the key figure in what many believe to be the most important North London derby for two decades.
There were, of course, two FA Cup semi-finals in quick succession in the early Nineties – one win apiece – but if Tottenham avoid defeat today they will be even better placed to finish above Arsenal for the first time in Arsène Wenger's reign, secure a Champions' League place and increase the pressure for a radical change of philosophy, if not of manager, at the Emirates.
It would darken Wenger's mood even further if a prominent role in that unholy trinity of achievements was played by Emmanuel Adebayor, who not only belongs to Manchester City but was one of those employees who left Arsenal to take the money on offer elsewhere.
The fees handed over by City for Adebayor and Kolo Touré were so vast (£41m for the pair) that it seemed good business at the time; yet the subsequent departures of Samir Nasri and Gaël Clichy for the same destination last summer, on top of losing Cesc Fabregas, helped bring about a changed landscape. "Where we are in trouble is not with our policy, it is keeping our players when they leave for bigger wages," Wenger said on Friday.
Spurs for their part are merely delighted to have secured Adebayor on loan for the season, their defenders in particular being well aware of what he has to offer. As their centre-half Michael Dawson puts it: "He seemed to score a lot against us. He's a big, strong boy, 6ft 4in, he can hold it up, head it, he's quick, he's a handful to play against and you know you are going to be in a game. Against Newcastle he was unplayable."
It is the first time that the Togolese striker has returned to the Emirates as a Spurs player and he will face even more abuse from the Arsenal supporters than he suffered during their 2-1 defeat at White Hart Lane in October.
Dawson is confident that Adebayor will cope: "Ade is mentally a strong guy, he has been at places and had abuse before, and I'm sure on Sunday he will be the same. "
Listen to the pessimists among fans of the two teams and the conclusion would have to be that both will lose the game. Arsenal have many followers who have lost faith in some combination of their players and manager; Tottenham's doubters look at third place in the table with a 10-point lead over the enemy and worry that it is all too good to be true.
The only cloud on Spurs' horizon is the prospect of losing their manager. Harry Redknapp has won so many plaudits for his achievements at White Hart Lane that the Football Association are expected to ask him to fill the gap left by Fabio Capello's departure as England manager. To try to combat that Spurs have apparently offered Redknapp a much improved deal to persuade him to stay until 2015, two years beyond his current contract. The mood in the Spurs dressing-room remains positive. "Third in the League," says Dawson. "We deserve to be there, well into the season. This is a different feeling to anything that we have had here before."
The secret to countering Arsenal's passing game is one that Spurs seem to have worked out, having lost only one of the past eight derbies. "You have to press them high up and keep the ball," says Dawson. "But we will concentrate on our own game, go there with pace and quality, and we believe we can beat them."
Wenger refused to concede any inferiority: "I believe we are more than capable of competing with them. In terms of what we have achieved over the last 10 years there is no comparison."
Then he launched into an attack on the financial irresponsibility of other rivals: "What is unbelievable is that we run the model like it should be absolutely normal and we look crazy. People who don't do something stupid are not crazy. We spend £1 when we make £1. That is what is absolutely mad in this world. The whole world is bankrupt because of this." Another failure today and the bitterness will only increase.
Arsenal v Tottenham Hotspur is on Sky Sports 1 today, kick-off 1.30pm