Sir Alex Ferguson would have taken only a qualified pride in the fact that this victory over Stoke City led Manchester United to consolidate their position as the highest scorers in the Premier League. He will be all too conscious that the side is under pressure to be prolific when the opposition have good cause to suppose they will do harm of their own.

For all the buccaneering spirit, Ferguson cannot be happy that the prolific ways seem a necessity as much as a sign of an adventurous spirit. There are reasonable explanations for the defensive brittleness when Nemanja Vidic as well as Chris Smalling and Phil Jones are absent through injury. In the circumstances it was natural that the side appeared brittle although Stoke would still have coveted the footballers who were available to United.

Wayne Rooney scored and took his club tally, including the years with Everton, to 200 goals. His impact and that of the other attackers is critical when the defence has already been breached 11 times in the league. It is the sort of statistic associated with sides in the less glamorous areas of the table. Despite Saturday's result, Stoke still have a better defensive record than United.

This is academic for the moment but Braga might not be feeling quite so fatalistic about Tuesday's Champions League match at Old Trafford. For all that, United can count on the know-how they possess in this European tournament. On their own pitch they have the knack of winkling out wins. That trait was conspicuous, too, against Stoke.

United made light of the imperfections. Ferguson stationed Paul Scholes and Michael Carrick near to the back four, yet the arrangement is far from ideal and neither looks a perfect fit. No one, for instance, would wish to see Scholes make one of his more reckless challenges in that area and it was debatable, too, if Carrick was truly shaping the play from so deep a position.

The vindication of the arrangements lies, of course, in the result. Ferguson had a line-up that completed its task without undue stress. He must have been satisfied by the thought of the players who had either been excused the game or, in the case of Ryan Giggs, were left unused on the bench.

Stoke intended to be stuffy but there was plenty of ventilation once United had blown holes in their line-up. Tony Pulis, the visitors' manager, must have hoped that his side would be stern. Until the team got to Old Trafford they had not conceded more than two goals in any Premier League match during this campaign.

Despite all the attention paid to United, there is something slightly enigmatic about them at present. They might even be termed an unknown quantity where the Champions League is concerned.

Last year, after all, they finished behind Benfica and Basel in their group and then lingered in the Europa League only until March.

Ferguson himself is under no illusion about the present level of performance. "We keep starting badly in games," he said. "We conceded an early goal against Fulham, an early goal against Tottenham, an early goal [against Stoke] but there's a goal threat about us."

Rooney was certainly a menace before he had notched his first goal of the campaign for United. His impact, indeed, was excessive when he headed a set piece past his own goalkeeper David de Gea in the 11th minute as he attempted to mark Ryan Shawcross.

The remainder of the afternoon suggested that United may be a side whose verve is on the rise. After 27 minutes Robin van Persie delivered from the left and Rooney rose to tie the score. The Dutchman took a goal for himself on the verge of half-time, converting Antonio Valencia's delivery to establish a 2-1 lead.

Shortly after the interval Rooney set up Danny Welbeck to glance home a header before adding to his own account, although the weariness in the visitors' defence was a factor when they failed to clear, so leaving him to finish in the 65th minute. By then Stoke had struck through Michael Kightly as the home defence was undone when the ball broke back to him off Rio Ferdinand.

There was more than enough incident to hold the crowd's attention, yet there was a haphazard tone to the occasion. United, given the status of the Champions League, must have had their real focus elsewhere. There was no role at all for Shinji Kagawa as well as Giggs.

Ferguson referred to his 15 different scorers so far this season. Without reaching peak intensity, United still made it impossible for Stoke to deal with the breadth of their repertoire.

Man of the match Wayne Rooney (Manchester United)