Arsenal take on last season's Champions League finalists Borussia Dortmund tonight, knowing that a win will leave them with one foot in the latter stages of the competition.
The Gunners have taken six points from a possible six in Group F following victories over Marseille and Napoli - but tonight's clash against Jurgen Klopp's men promises to be their biggest test so far.
Arsene Wenger, on his 64th birthday, is expected to stick with the side that comfortably beat Norwich City 4-1 on Saturday. However, the Frenchman will be without tenacious defensive midfielder Mathieu Flamini, who has been ruled out of the match with concussion.
Flamini has been one of Arsenal's best players since returning to Emirates Stadium in the summer, but Wenger is likely to call on Mikel Arteta to do a similar job.
Alongside the Spaniard should be Aaron Ramsey, the in-form Welshman who came off the bench at the weekend to score another special goal.
Wenger might be tempted to start former Borussia Dortmund star Thomas Rosicky, though, while Jack Wilshere and Santi Cazorla should occupy the right and left flanks, respectively.
Mesut Ozil will drift in and out of several positions, but should start as the attacking midfielder behind Olivier Giroud.
The defence, meanwhile, handles itself.
Arsenal's predicted XI:
Goalkeeper: Wojciech Szczesny
Left-back: Kieran Gibbs
Centre-back: Laurent Koscielny
Centre-back: Per Mertesacker
Right-back: Bacary Sagna
Central midfield: Mikel Arteta
Central midfield: Aaron Ramsey
Left-wing: Santi Cazorla
Attacking-midfield: Mesut Ozil
Right-wing: Jack Wilshere
Striker: Olivier Giroud