LONDON - Arsene Wenger believes Arsenal's Champions League double-header against Borussia Dortmund will be "decisive" in the race to qualify from Group F.
Wenger's side host last season's runners-up on Tuesday before heading to Dortmund for the return on matchday four.
The Gunners are currently top of their group following back-to-back wins over Marseille and Napoli.
Wenger knows another three points on Tuesday will leave Arsenal in pole position to reach the knockout stages, but he is also well aware that Dortmund could deliver a major blow to his side's qualification hopes.
"Dortmund have grown a lot and they look a different proposition now, maybe they were a bit impressed by us in the first group games when we met them in 2011, but this time they have gained confidence," Wenger told UEFA.com.
"I feel we are stronger as well this season, so I think it will be very interesting.
"It is already a very important tie because usually matchday three and four usually are decisive, so that could be the key for us to qualify."
Wenger, whose side are two points clear at the top of the Premier League following Saturday's 4-1 win over Norwich, has a wealth of options to ponder in midfield, with the return to match fitness of Santi Cazorla following an ankle injury.
Aaron Ramsey started on the bench against Norwich but replaced Mathieu Flamini just before half-time after the French midfielder suffered double vision following a clash of heads with Alex Tettey, leaving him rated as doubtful for the Borussia tie.
"We have a squad that is, number and quality wise, very, very good. After that in January we are not desperate (to buy) now," Wenger said.