Arsene Wenger is facing up to a defensive selection headache after Shkodran Mustafi was ruled out of Sunday's huge encounter between Arsenal and Manchester City.
The London Evening Standard has reported that the centre-back will be absent from the Gunners' squad for the trip to Emirates Stadium after he failed to recover from a groin strain.
With Callum Chambers also injured, Laurent Koscielny suspended, Sead Kolasniac rated 50/50 and Per Mertesacker unable to play three games in the space of a week, Wenger now has a dilemma on his hands over who to play in his backline to take on Pep Guardiola's breathtaking attacking outfit.
Mustafi had hoped to be fit enough to play some part in the away game against the Premier League leaders, but the Germany international will not have recovered in time to feature.
The 25-year-old sustained his latest injury whilst on international duty - Mustafi being forced from the field of play after 36 minutes in the 5-1 thumping of Azerbaijan on 8th October.
He has missed the last eight Arsenal matches due to the strain, and is not expected to return to full training until the next international break ends around 18th November.
Wenger's charges, who are known for their defensive vulnerability, would likely struggle against City's fearsome attackers but the absence of some key players could make their task even harder.
The Frenchman has the option of deploying Mohamed Elneny as a makeshift centre-half to play alongside the likes of Nacho Monreal, or start youngster Rob Holding and hope his lack of pace and experience aren't too much of a hindrance.
Wenger could also rest Mertesacker for Thursday's Europe League home clash with Red Star Belgrade and then use the veteran defender against City but, again, his lack of pace would be no match for City's lightning quick forwards.
If Kolasinac, who is nursing a slight groin problem himself, is also unavailable then Monreal would have to fill in at left wing-back - another issue that Wenger would have to contend with.