Graphic: The key clashes - Aalborg v Manchester United & Arsenal v Porto

The messages on the billboards dotted around Aalborg airport and this quiet city in Denmark's far north told their own story. “Manchester United are welcome in Aalborg,” they read.

It is hard to imagine the European Cup holders being made to feel quite so welcome in Milan or Madrid, but whether it was Thomas Augustinussen, the Aalborg captain, expressing wonder at the number of people who attended the obligatory press conference or Bruce Rioch, the Danish club's coach, talking about the visit of United being the “biggest game in our history”, it was hard to escape the feeling of a town and a team star-struck by the rare presence of footballing royalty.

Cristiano Ronaldo has not been asked for so many autographs since he was last in Asia, while Sir Alex Ferguson was heralded as the “man of the century” upon his arrival, but if Aalborg were trying to lull the United manager and his players into a false sense of security, they do not appear to have succeeded.

The proof will be when David attempts to topple Goliath at the 13,800-capacity Energi Nord Arena this evening, but Ferguson has learnt from experience after a chastening last visit to Denmark two years ago.

United had won their opening three Champions League group games when they travelled to play Copenhagen in November 2006 and paid the price for fielding a weakened team, with Marcus Allbäck's goal consigning them to a surprise 1-0 defeat.

Another single-goal loss in their next game, away to Celtic, ensured that progress from the group was not as smooth as it should have been. But, after a goalless draw in their opening group E game against Villarreal at Old Trafford 13 days ago and with Celtic up next, Ferguson will be taking no chances this time around.

“Aalborg are a small club, there will only be about 10,000 people here, but the most important thing they get from Manchester United is our respect,” he said. “We have to make sure we don't fall into any traps and that we play to our best level and play our best team. Two years ago, I made the mistake of picking a team against FC Copenhagen based on the fact that we were in a comfortable position at that moment and we ended up scrapping away to get qualified, so we will be playing our strongest team.

“The players realise and know how important qualifying from the group stage is. They and I always believe that the tournament kicks off at the end of February [when the knockout rounds start] and if we get to that stage, which hopefully we will, then we have as good a chance as any of them, but the important thing is to qualify.”

With Gary Neville, the United captain, left behind because of a slight thigh strain and Owen Hargreaves again absent after suffering a recurrence of tendinitis in his knee, Wes Brown should deputise at right back, while Paul Scholes is likely to return to central midfield after missing the Villarreal game through suspension.

Wayne Rooney, who came off the substitutes' bench to claim his first goal of the season in the 2-0 win at home to Bolton Wanderers on Saturday, should also start, although most eyes are likely to focus on his strike partner, Dimitar Berbatov.

Despite showing glimpses at the weekend of the talent that persuaded Ferguson to pay Tottenham Hotspur £30.75million for the Bulgarian last month, Berbatov has yet to score in four matches for his new club, but Rioch, like Ferguson, has no doubts that the forward will come good.

While in charge at Arsenal in the mid-1990s, Rioch had to wait seven games before Dennis Bergkamp, whom he had signed for £7.5million from Inter Milan, scored, but the wait was worth it and by the time the Dutchman left North London more than a decade later, he had cemented his status as one of the club's and Premier League's greatest players. Rioch believes Berbatov is in the same mould as Bergkamp and could have a similar impact.

“Like Dennis, Berbatov is silky, classy with a good touch and has scored goals,'' Rioch said. “Sometimes moving from one club to another takes time to adjust, but he's a talented player and Sir Alex doesn't make too many mistakes.”

Berbatov has not been helped by United's indifferent start to the season, but just as he insisted that he is not “scared” by the challenge facing him, so Aalborg are adamant that they will not be intimidated by illustrious opposition.

Abstaining for a moment from the hero worship exhibited towards Ferguson, Rioch claimed that an upset would send an “earthquake” through football, but, having taken seven points from their opening eight league games this season, Aalborg would appear to have their work cut out just keeping the score respectable. Not that they don't dare to dream, however. “We are story writers and want to write another story,” Augustinussen said. Not if Ferguson has anything to do with it.