With two matches played, it appeared that Arsenal, on six points, were going to cruise through to the knockout stages of the Champions League.
However, the 2-1 defeat last time out to Borussia Dortmund has muddied the water somewhat. The Gunners are now locked on the same points as Dortmund and Italian outfit Napoli.
On Wednesday, Arsene Wenger's side will travel to Germany for the return match with Dortmund. The Yellows have played eight games at home this term, winning all of them. What's more, they won all six of their home matches in the competition last term.
Injuries have ruled both Sebastian Kehl and Ilkay Gundogan out of the clash, while full-back Lukasz Piszczek will sit out the contest following summer surgery to fix hip and groin problems.
Meanwhile, Mathieu Flamini will be absent for Arsenal because of a groin complaint. There is also a doubt over the availability of both Jack Wilshere and Kieran Gibbs because of injury.
The two sides have met in Germany on two previous occasions, with Dortmund winning back in 2002 thanks to two goals from now Arsenal midfielder Tomas Rosicky. The other encounter, in 2011, ended in a 1-1 draw.
Recent form
Dortmund: WLWWWW
Arsenal: DWLWLW
Possible starting lineups
Dortmund: Weidenfeller; Grosskreutz, Hummels, Subotic, Schmelzer; Sahin, Blaszczykowski, Bender; Mkhitaryan, Reus; Lewandowski
Arsenal: Szczesny; Vermaelen, Koscielny, Mertesacker, Sagna; Arteta, Ramsey, Rosicky; Ozil, Cazorla; Giroud
Sports Mole says: 2-1