Arsenal are back in the land of their revival. When Arsène Wenger and his team last visited Germany they defeated Bayern Munich in the Champions League. It was not a result that had seemed likely and it did not spare them elimination from the last 16 of the competition but its restorative powers have come to look startling.

Since that evening in mid-March Arsenal have played 13 times on the road in three competitions. They have won 12 and drawn one – the lone blot being the 1-1 Premier League draw at West Bromwich Albion.

It was a different Wenger and a different Arsenal that arrived in Dortmund on Tuesday, seeking the Champions League victory that could spare them an awkward trip to Napoli on the final evening of Group F fixtures. If any further motivation were required, it was provided by Dortmund's smash-and-grab win at the Emirates Stadium two weeks ago.

The confidence within Arsenal's ranks these days is palpable. Wenger cut a relaxed figure as he answered one question in German and also chided the translator for his attempted pronunciation of Serge Gnabry, who is back in the squad after ankle trouble. "He's German," Wenger said, with a smile. Along the table from Wenger, Olivier Giroud spoke about his encouraging start to the season. "The difference with the last season is especially the confidence," the France striker said.

Arsenal play at Manchester United in the league on Sunday, a game in which victory for them could prompt an upgrade of their title-contender status. But Wenger had no thought of Old Trafford; he will not pick his team here with United in mind. It is expected that he will persist with the XI that started in Saturday's home win over Liverpool. Wenger is intent on harnessing the momentum.

"We do take belief from Munich last season," he said. "We play everywhere to win. That will not change and we will have a positive attitude to this game. Maybe we had not the same belief at home because we failed in a few big home games. You could feel there was a bit more scepticism and less belief at home, although hopefully we have got that behind us now after Liverpool." Wenger's injury update took in good news on Kieran Gibbs, who is "completely available" after limping off against Liverpool, and Mathieu Flamini, who has not travelled due to groin trouble but "has a very good chance to be available on Sunday".

The bulletin on Jack Wilshere was less positive. The midfielder, who twisted his left ankle – the good one – last Thursday, remained in London, having been unable to train and he is a doubt for the United game. "If he is out for Sunday, then he will be out for England as well," Wenger said. He would surely not risk a half-fit Wilshere at Old Trafford if part of the reward was to make him available for England's Wembley friendlies against Chile and Germany.

Jürgen Klopp, Dortmund's manager, had his game-face on. He refused a request to speak in English and there was little levity about him. Arsenal's away form meant nothing, he suggested, as every game had "its own history". If Dortmund had won their last 70 home matches, it would not make "any difference" against Arsenal.

Klopp was rather more quotable when he gave an interview to the Guardian, in which he likened Wenger's approach to that of a silent orchestra and his own to heavy-metal madness. "I am not a great specialist in music," Wenger said. "Dortmund is a very good football team and Arsenal as well … therefore we should see a good symphony."

Wenger did give his thoughts on Klopp's obsession with the Dortmund players covering more kilometres than their opponents to lay the foundations for victory. "It is not how much you run but where you run and how intelligently you run," Wenger said. "Very usually the teams who have less of the ball run more."

Wenger intends to stifle Dortmund by hogging possession. It is Arsenal's away run that he prizes.