Arsenal's defensive injury crisis has deepened after Bacary Sagna was ruled out until the new year with a broken leg.
The French Football Federation last night confirmed the right-back had suffered a fractured fibula in yesterday's north London derby and is expected to be out for three months.
The 27-year-old was taken to hospital after being carried off on a stretcher during the second half at White Hart Lane.
The FFF statement read: "The doctor of the France team, Fabrice Bryand, was informed by Arsenal of a fracture to the right fibula of Bacary Sagna.
"The player was hurt during the match lost 2-1 by his club against Tottenham on Sunday. The defender will be operated on and is not expected to be available for three months."
Arsenal's 2-1 defeat saw their defensive frailties brutally exposed again as they were beaten for the fourth time in seven Barclays Premier League games this season, and the loss of Sagna merely compounded their misery.
The Gunners were already without Thomas Vermaelen, Johan Djourou, Sebastien Squillaci and Laurent Koscielny yesterday and were again forced to play Alex Song as a makeshift centre-half.
And although they enjoyed more of the ball than Tottenham, they were carved open all too easily, leaving them 12 points adrift already of Manchester United and Manchester City.
Manager Arsene Wenger all but conceded the title, saying: "At the moment, we have to set realistic targets and to get in touch with teams that fight to be in the Champions League positions.
"To say today 'we will win the league' is not realistic.
"But we have to fight to come back into a better position."
Arsenal are only two points above the drop zone but although Wenger dismissed the threat of relegation, his side also looked nowhere near threatening the top four.
"We lack a little bit of confidence at the moment and just want to protect our result too much when we have one," the Frenchman said after watching Aaron Ramsey cancel out Rafael van der Vaart's controversial opener only for Kyle Walker to score the winner from 30 yards.
Tempers flared at full-time when Wenger and Spurs coach Clive Allen clashed after the latter felt the Gunners boss had snubbed his offer of a handshake.
Accusing Allen of making something of nothing, Wenger said: "I shook the hand of the manager and the assistant manager.
"How many people do I have to shake hands with? Is there a prescription?"
Wenger was less confrontational when it came to the offensive chanting that marred the game from both sets of supporters.
The Arsenal boss is a perennial target for Spurs fans, while some of the visiting contingent mocked Emmanuel Adebayor about the tragic killing of his Togo team-mates during last January's African Nations Cup.
Wenger was disappointed by the chants, adding: "We respect everybody and we want to be respected."