Former winners Borussia Dortmund host Arsenal in their Champions League Group F opener on Tuesday, with both sides desperate to drag themselves out of an early slump this season.

Arsenal are not in the best of shape for Tuesday's encounter with manager Arsene Wenger starting the first game of his two-match touchline ban and injuries keeping out key defender Thomas Vermaelen and midfielder Jack Wilshere.

At least the Gunners finally got their domestic campaign up and running when they beat Swansea City 1-0 for their first Premier League win of the season with a hugely fortuitous goal from Andrei Arshavin at the Emirates on Saturday.

Despite the win and some good midfield approach work from new signing Mikel Arteta, it was another nervy performance from Wenger's men albeit an improvement on their 8-2 defeat at Manchester United two weeks ago.

"We started quite well, but the nerves took over and we played with the handbrake on," Wenger, who lost his appeal against his UEFA ban last week, said.

"Confidence goes quickly, and comes back slowly, and for us to be in the situation we are in, we are not used to that. We need to put a few wins together."

Defender Per Mertesacker, making a quick return to his homeland after joining Arsenal at the end of the transfer window, has told his team mates they face a tough task in Germany.

"Dortmund were the best team in Germany last year, they do a good job passing the ball and have great players," the Germany international said.

"It will be difficult for us but I know we have very good players and I am confident we can get a result.

"Dortmund are the toughest opponents in our group so we will be very happy if we take something from this match," Mertesacker added.

Dortmund, however, are a shadow of last season's explosive team and a 2-1 home defeat by Hertha Berlin on Saturday has done little to calm nerves before the game.

With just seven points from five league games and already two defeats, Dortmund know they must up their game against the English side.

The 1997 Champions League winners slumped to their first home defeat in 18 league games stretching back to August 2010 with yet another uninspired performance.

Coach Juergen Klopp will be relieved to have Mario Goetze back in action after the 19-year-old midfielder missed the league game through suspension.

"We can play much better than we did against Hertha and with a lot more creativity," Klopp said.

Top striker Lucas Barrios, who has recovered from a muscle injury that caused him to miss the start of the season, could make a return despite coming back to training only last week.

"We need to turn our weaknesses into strengths against Arsenal," central defender Neven Subotic said.

"Saturday's performance is not enough. It is not enough for the Bundesliga and most certainly not enough for the Champions League," he added.