“It was one of the turning points of the season. Why? Because of our fans, because we had more not bought, because Tottenham had bought 10 players.

“Everybody was bit shocked and surprised by the fact that we could win this game. But it was important for the belief around the team more than inside the team. We had the belief that we could beat Tottenham [that day] but even our direct environment was very sceptical about it.”

That was Arsène Wenger on Friday talking about Arsenal’s victory in the north London derby back on September 1. The two sides meet again for a mouthwatering FA Cup third-round tie on Saturday with the effects of that previous encounter still being felt.

In one week you can go very high up and as well low down. That's what makes this sport so difficult to manage but it's fantastic when it goes the right way

Arsène Wenger

Before kick-off late last summer, the opening-day defeat to Aston Villa felt fresh enough in the mind and, as the Arsenal manager admits, there was concern over the lack of a major addition to the squad.

After all this time, we should have known better.

Olivier Giroud squeezed home a goal in the first half then a bullish home defence held off the Tottenham push after the restart. By the time, a day or so later, Wenger secured the signature of Mesut Ozil and the mood had swiveled 180 degrees.

But it is important to remember the manager had been panel-beating his side into shape all year so they could be an overnight success. The statistics just revealed at the end of 2013 prove beyond doubt Arsenal were already morphing into a formidable outfit before that derby and before Ozil signed on the dotted line.

However both combined to give the Club a massive injection of positivity. One that has helped Arsenal stay at the top of the Premier League table for nearly four months virtually without a break.

“We live in a society that is characterised by speed and football is even speedier than the society,” said Wenger reflecting on the about-turn in opinion that was sparked by that victory. “In one week you can go very high up and as well low down. That's what makes this sport so difficult to manage but it's fantastic when it goes the right way.”

And that was truly a fantastic few days.

Of course, Arsenal’s very success in a nip-and-tuck Premier League title race opens the questions of resting key players for a game in the ‘third’ competition. However the manager loves the FA Cup and will only rotate where he feels he has no choice - especially as his side have a nine-day break after this game before they go to, of all places, Aston Villa.

“We have one or two who are at the limit because they played many, many games and there is a big danger they could be injured,” he said. “They will be rested but, apart from that, you want to win the game and we have a big break after this match.”

They bought good players. At some stage when the team finds a way and the right balance they can be very dangerous

Arsène Wenger

Nicklas Bendtner is definitely out with an ankle injury. Giroud has recovered from a similar problem but he went down with sickness on Friday morning. Therefore Wenger has a quandary about the pivotal role up front.

“It leaves my thoughts with the players that you know - that means it can be Podolski, Walcott or Ozil if he is available,” said Wenger. The German was classed as a doubt with a shoulder problem at Wenger’s press conference on Friday but did train later that day.

Tottenham dispensed with the services of Andre Villas-Boas after a 5-0 drubbing at home to Liverpool in mid-December. His replacement, Tim Sherwood, started with a Capital One Cup exit at the hands of West Ham but the side has recorded three wins and a draw since then - the last of which came at Manchester United on New Year’s Day.

Former Arsenal striker Emmanuel Adebayor scored at Old Trafford and has been one of the key changes introduced by Sherwood. But, as Wenger asserts, Tottenham were the sternest of tests at Emirates Stadium back in September but maybe that pack of new players had yet to bed down. The process has moved on a few months since then.

“They bought good players,” said Wenger. “At some stage when the team finds a way and the right balance they can be very dangerous.”

On current form Tottenham are certainly in that category.

The prevailing winds behind these two sides have changed dramatically since the start of the season and defeat on Saturday would bring forth another negative gust.

The winners, however, will be flying once more.

Arsenal v Tottenham is always massive but a potentially season-changing game in the FA Cup third round merely multiplies the magnitude.

Game on.

Team news:

Arsenal: Giroud (doubt - sickness), Ozil (doubt - shoulder), Bendtner (ankle), Ramsey (thigh), Gibbs (calf), Sanogo (back), Diaby (knee), Oxlade-Chamberlain (match-fitness).

Tottenham: Naughton (hamstring), Lamela (hip/thigh), Sigurdsson (calf), Paulinho (ankle), Vertonghen (ankle), Kaboul (hip).

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source Richard Clarke 3 Jan 2014