Unai Emery's future as Arsenal coach was plunged into further doubt on Thursday when the Gunners slumped to a 2-1 loss in the Europa League against Eintracht Frankfurt.
Arsenal are now winless in seven games, the club's worst run since 1992.
“Positive but above all realistic. We missed a good opportunity tonight to win the match,” Emery told broadcasters BT Sport.
Japan midfielder Daichi Kamada's second-half double for the Germans came after captain Pierre-Emerick Aubameyang had opened the scoring in first half injury time for Arsenal inside a half-full Emirates Stadium.
Boos from the lowest attendance at the ground since it opened in 2006 greeted Emery and his misfiring team at the final whistle while some disgruntled fans held up banners demanding 'Emery Out'.
Aubameyang struck home just before the half-time whistle with a low effort for his ninth goal in 14 matches.
Kamada's equaliser came 10 minutes later as he curled a tidy shot past Emiliano Martinez before adding his second on 64 minutes with a drive from outside the box to inflict a first home defeat of the campaign on Emery's men.
The Gunners are still on course for a last 32 place if they draw with Standard Liege on December 12.
Scottish champions Celtic clinched top spot in Group E with a 3-1 win over Rennes while Wolves reached the knockout stages with a 3-3 draw at fellow qualifiers Braga in Group K.
Rangers drew 2-2 at Feyenoord to hold top spot in Group G with a one point lead ahead of their last game against Young Boys.
Earlier, Roma's Lorenzo Pellegrini was hit by coins as the Italian club kept their last 32 hopes alive with a 3-0 victory at Istanbul Basaksehir.
Attacking midfielder Pellegrini had his head bandaged after he was struck by multiple coins with an hour of the game played after Jordan Veretout, Justin Kluivert and Edin Dzeko had claimed the advantage for the Serie A outfit in Turkey.
The visitors remain in contention for a knock-out spot and sit behind leaders Borussia Moenchengladbach, who beat Austrians Wolfsberg 1-0, on goal difference with the Turkish side a point behind on seven.
