Arsenal and Manchester City meet at the Emirates Stadium on Saturday evening with recent results meaning that only one of them is considered to be genuine Premier League title contenders.
City's 3-0 victory over rivals Manchester United in midweek took them to within three points of table-topping Chelsea, and they still have two games in hand.
A second straight match without a win - a 2-2 draw at home to Swansea on Tuesday, has left the Gunners six points back and Arsene Wenger admitting that finishing in the top four is now their priority.
With next weekend's opponents Everton only six points behind them, having played a game fewer, Arsenal now have a fight on their hands to secure Champions League qualification.
Theo Walcott, Aaron Ramsey and Mesut Ozil remain key absentees for the visit of the Citizens, while a predicted two-week layoff for central defender Laurent Koscielny comes as a huge blow to Wenger.
Club captain Thomas Vermaelen will continue alongside Per Mertesacker at the back, with Bacary Sagna, who has been linked heavily with City this week, taking up his usual place at right-back.
Wenger may restore Lukas Podolski to the XI after the German scored and assisted as a substitute against Swansea. With Mathieu Flamini likely to start to give greater protection to Arsenal's defence, which has conceded 17 goals in five games against the top three, Alex Oxlade-Chamberlain may be sacrificed.
Manuel Pellegrini has no new injury worries ahead of their trip to North London, where they put five past Tottenham Hotspur earlier in the season, but Sergio Aguero is still nursing a hamstring strain.
Reported Arsenal target Micah Richards and Matija Nastasic are also unavailable, so Pellegrini may name an unchanged lineup from the one that was victorious so convincingly at Old Trafford.
Edin Dzeko is expected to start in attack after scoring twice in the derby, with the City manager's only possible selection dilemma be between former Gunner Gael Clichy and Aleksander Kolarov at left-back.
Recent form
Arsenal: DLWDWL
City: WWWLLW
Possible starting lineups
Arsenal: Szczesny; Sagna, Mertesacker, Vermaelen, Gibbs; Arteta, Flamini; Rosicky, Cazorla, Podolski; Giroud
City: Hart; Zabaleta, Kompany, Demichelis, Clichy; Fernandinho, Toure; Navas, Silva, Nasri; Dzeko
Sports Mole says: 0-2
No Data Analysis info
