Last year runner's up are currently winless in their domestic league but have travelled to Hamburg for their Group G clash with a new purpose.
"Let's focus on Europe. If we get a good result in Hamburg we'll go in good condition to Man United," Arsenal coach Arsene Wenger said referring to Sunday's blockbuster back in England.
"I can't say that I am unconcerned by our start to the season. We are lacking a bit of sharpness because half the team has been away for the whole summer playing football."
The story is the same for the hosts who have also had a winless start to the Bundesliga.
"We are in a dip at the moment but we need to forget about the cup loss and concentrate on Wednesday's match against Arsenal," said Hamburg coach Thomas Doll.
"We need to show a positive reaction and I am sure my team will do that."
New Arsenal signing William Gallas is likely to remain at left back, the position he found so unpalatable at Chelsea.
The other Group G clash sees Porto host CSKA Moscow.
Lyon ready for galaticos
In Group E Lyon begin their quest to qualify past the quarter-finals after their campaigns ended at that stage for the past three seasons.
The French side host Spanish giants Real Madrid, who despite a string of big name signings have endured a number of trophyless seasons.
Madrid again opened the cheque book in the off season and secured the services of Italian captain Fabio Cannavarro, strikers Jose Antonio Reyes and Ruud van Nistelrooy and former Lyon midfield enforcer Mahamadou Diarra who will no doubt face the wrath of the home fans.
van Nistelrooy scoring again in
The Mali international has been replaced by Jeremy Toulalan who is ready to fill the sizeable void.
"I'm nobody's successor, but I want to make sure I give it 110 percent," Toulalan told the Dauphine Libere newspaper.
"I have to make sure I am at the service of the team, which is a little bit different to being at Nantes when I was allowed to roam the midfield.
"Here, I'm given orders and I obey them. But that's fine with me. The important thing for me is to play.
"If they asked me, I would play as a right-back against a team like Real."
Victory to either side would be seen as a major step towards topping the group with remaining sides Dynamo Kiev and Steaua Bucuresti relative minnows who face each other in the Ukraine tonight.
Bhoys head south
The cliché "Battle of Britian" has been bandied around the British tabloids as Manchester United host Glasgow Celtic in a match which is likely to see the return of the Red Devils' Wayne Rooney and Paul Scholes to competitive football.
United were humbled in last year's Champions League when they finished at the bottom of their group however manager Sir Alex Ferguson is convinced it will be different this year.
"It will be different this year I can assure you," said Ferguson.
"If someone had told me this time last year we would finish bottom of our group, I would never have believed them.
"No one likes bad memories but good footballers should always look at situations like that and say 'I do not want that to happen again'."
Their opponents have had a busy off season with plenty of new arrivals, something which may impact on their performance tonight.
"We are still getting to know each other as we go down to Old Trafford, but that is football," said new Dutch striker and human tongue twister Jan Vennegoor of Hesselink.
"It is always difficult to play there - I've been there before with PSV Eindhoven and know it's not easy. But if we play as a team, maybe we can do something there."
Last season's surprise packet Benfica travel to FC Copenhagen to round out Group F.
Corruption tainted Italian side AC Milan must be just happy to be involved in this year's Champions League as expulsion looked likely months ago.
After qualifying for Group H the Rossineri will again be one of the favourites but they remain humble ahead of their match against AEK Athens.
"It's a fascinating tournament and always difficult," Serginho told AC Milan's official website.
"AEK are a proud team and they will come here looking for a win. We will have to show our quality and strength."