Such is the nature of the English Premier League this season that a couple of games without a win and you will be left behind in a terrific race at the top of the table.
Arsenal, flying high and bossing the league for much of this season, could find themselves in fourth, albeit only a point behind the leaders, if they fail to get a single point in their home game at the Emirates against Chelsea.
Nine times Arsene Wenger has attempted to get one over Jose Mourinho, and nine times he has failed. To pick up a win, while not being paramount, does hold so many intangible and psychological edges going into the second half of the season, that the importance of a positive result for either side cannot be stressed enough.
For Arsenal it is just another stop, of a seemingly endless train of stops, towards proving they are title-worthy; something that has been seriously questioned following that big 6-3 defeat at Manchester City nine days ago.
"At the moment everybody still questions us," Wenger said. "We haven't won it [the Premier League] for a long time, that's why they question us.
"It [the possibility of going fourth] adds pressure but you cannot play in the Premier League without pressure. There are periods where the pressure is a bit bigger and periods where it is smaller.
"You have to live with that and resist that kind of stress."
Liverpool's win over Cardiff and Manchester City's triumph at Fulham have pushed Arsenal down to third, with Chelsea currently in fifth, following Everton's positive result on Sunday.
If Arsenal lose, they will drop down to fourth, with Chelsea, two points behind their Monday opponents at the moment, moving level with leaders Liverpool. But if the Gunners win, then they will be where they have been for the majority of the season, looking down at the rest of the chasing pack.
Mourinho has in the past scoffed at Arsenal's title credentials in the past few season, while admiring the Premier League view from his job at Real Madrid and Inter Milan, but the Portuguese, who has had a few run-ins with Wenger in the past, including that infamous "voyeur" saga, now believes the fellow London side are the real deal and could be right up there with the best fighting for the Premier League crown.
"To arrive at Christmas time at the top of the league is a sign they are fighting for the title, they have the squad so they have the conditions to do it," Mourinho said.
"Up until now they are the strongest team, they have more points than anybody else and they have already played Manchester City, Liverpool, Tottenham and Manchester United, so the Chelsea game will be the last match against the other contenders."
Team news: Arsenal: Jack Wilshere is suspended for the next two games after being found guilty of improper conduct in the game against Manchester City last Saturday, while Laurent Koscielny is "80-90 percent" ruled out. Alex Oxlade-Chamberlain, Yaya Sanogo and Abou Diaby remain sidelined, but Lukas Podolski is set to make a return for the first time since late August.
"It's a big boost because he can score goals in big games," Wenger said on Podolski's return. "He has shown that before. He is a clinical finisher and a great football player."
Chelsea: Apart from Marco Van Ginkel, Mourinho does not have too many problems, as Ashley Cole is set to miss out against his former side, with the manager to continue persevering with Cesar Azpilicueta at left-back.
"I feel at this moment he's playing better [than Ashley Cole]," Mourinho said. "He's showing me that physically he's very strong and focused on the defensive job.
"I don't remember one defensive positional mistake from Azpi and when you are going to face people like [Mesut] Ozil coming from the right, [Theo] Walcott making diagonal runs or [Tomas] Rosicky attacking defenders with the ball at his feet, he's a player I feel has to play."
Key men: Arsenal: Mesut Ozil has disappeared in the big games a little bit this season, but there is no better time for the German to shine than against Chelsea, whose manager Arsenal's record signing is quite familiar with.
"He's a phenomenal player, he's one of these players that you buy and you complete the puzzle of your team," Mourinho, who coached Ozil at Real Madrid, said. "You don't need time, you need nothing, he arrives and you have an empty space waiting for him, his quality, maturity and leadership. You know that automatically your team becomes better.
"There are players that you buy that you realise you need to work with, adapt or find the best solution to get the best out of them, but Ozil needs nothing. He arrived, Arsene gave him the shirt, immediately he starts playing and immediately the team becomes better.
"I think I know how to try to stop him being direct influence in the game for 90 minutes, but it's impossible to stop him for 90 minutes because these kind of players always have a moment, or a couple of moments where you cannot stop them and they end up showing why they are so good."
Chelsea: Eden Hazard will look to torment Bacary Sagna down the Arsenal right, while the midfielders and defenders will also need to be wary about the Belgian international cutting in and unleashing powerful shots with his right foot.
Where to Watch Live
The game is scheduled for a 1.30am IST start with live coverage on Star Sports 4 and Star Sports HD2. You can also catch all the action live online by clicking HERE. To watch the match courtesy live streaming in the U.S. click HERE, while U.K. viewers can click HERE. To live stream the match in the Middle East click HERE, to do the same in Australia, click HERE.
Expected lineups: Arsenal: Szczesny; Sagna, Mertesacker, Vermaelen, Gibbs; Flamini, Ramsey; Walcott, Ozil, Cazorla; Giroud.
Chelsea: Cech; Ivanovic, Cahill, Terry, Azpilicueta; Ramires, Lampard; Willian, Oscar, Hazard; Torres.