Roberto Mancini was relieved to see Manchester City win at Fulham at the weekend, because he did not wish to face Borussia Dortmund, the Bundesliga champions, on the back of a run of disappointing draws. "It was important to get back to winning, with such a big game coming up," the Manchester City manager said.

Sir Alex Ferguson probably feels the same way about Manchester United's hard-won, if not exactly commanding, victory against CFR Cluj. Some of the United defending was lacklustre and their usual approach of utilising the width of the pitch was abandoned in favour of a narrow attacking setup that relied on Wayne Rooney passing through the middle of the Romanian defence, but once Robin van Persie responded neatly to one of the best of Rooney's invitations the points were secured and Ferguson's players could begin to put the home defeat by Tottenham behind them.

It is important, as Mancini might say, that they do that, because the next game in the Premier League is Newcastle United away. Often a tricky fixture for Manchester United over the years – for some reason Roy Keane taking a swing at Alan Shearer and missing by a mile comes to mind before any actual results – last year's meeting at St James' Park, or the Sports Direct Arena, as it had just started to be known, produced a surprising and highly significant 3-0 victory for the home side.

Surprising, because Manchester United (apologies for using their Sunday name all the time, but Newcastle supporters rightly complain if the abbreviation United is assumed to refer only to the team in red) had just been beaten at home by Blackburn Rovers, of all teams, and some sort of backlash was expected on Tyneside. None came and, in the context of a league title won on goal difference with the last kick of the season, Manchester United squandering six points in two games at the turn of the year was as significant as any later twists and turns.

The result was hugely significant for Newcastle, too, as it confirmed to all the potential of the side Alan Pardew was assembling. As a team promoted only the season before, Newcastle were not thought likely to continue their early-season flirtation with the top four and had dropped to seventh by the time Manchester United arrived, but their convincing win over the defending champions and the timely arrival of Papiss Cissé in January turned them into genuine Champions League contenders over the second part of the season.

Ferguson's response to defeat in the north-east was to blame "strong winds" – whatever you think about the preposterousness of some of Fergie's excuses you have to admire the fact he always has one to hand, and a deadpan way of delivering it – and to hasten the rehabilitation of Paul Scholes. The midfielder officially reversed his decision to retire four days later though clearly he would have been preparing for a return for some time before that and, while he proved in the second half of the season that he had plenty of life left in him and had probably stepped down too early, it still came as a surprise – well, it surprised this correspondent – that several football writers were prepared to vote for him as player of the year. Everyone likes a fairytale, but over the course of the season Scholes had simply not been that influential. Even had Manchester United won the title, and they came extremely close, it would have been a sentimental award.

Scholes is still around and getting games, even though Ferguson has two younger players, Rooney and Shinji Kagawa, who can do more or less the same thing if required. That is, spread the ball out wide, on days when wingers such as Antonio Valencia, Nani or Ashley Young are available, or look up from midfield to see if a telling pass forward may be an option. Kagawa appeared to be the ideal solution to most of Ferguson's attacking wishes when he arrived at the start of the season, yet he was left on the bench against Cluj, Scholes was left at home and Rooney was withdrawn to midfield. You could not say the formation did not work, though you could not say either that Manchester United looked like a team capable of dominating some of the bigger names in Europe later in the competition.

Maybe they were just warming up, or maybe Ferguson was conserving energy and players for bigger tests ahead, such as the one at Newcastle this Sunday. In which case he will be more worried about his defence than his attack, with the increasingly uncertain Patrice Evra likely to be given a thorough examination by Hatem Ben Arfa, and Manchester United's perennially patched-up central defence almost certain to find Cissé and Demba Ba a handful.

The game at Newcastle last season came almost exactly at the halfway stage. This time it is earlier, but a second consecutive league defeat for Manchester United could still have the same effect, of suggesting Ferguson's players are back in the realms of mere mortals and can no longer boast the almost magical ability to turn round any result or seemingly lost cause through sheer force of personality. Most Premier League clubs can suffer back-to-back defeats without their raison d'être being questioned, but Manchester United are not most clubs. The drawback of constructing a myth of invincibility and indefatigability so successfully that opponents have frequently bowed to the myth instead of taking on the football team is that you have to try to keep it up for ever, because people notice when the mask slips.

On the basis of Manchester United's past two performances, the mask is in danger of slipping, and Ferguson could have asked for a better time to play Newcastle away. That said, Newcastle could have picked a better time to play Manchester United than four days after a Europa League game against Bordeaux. Not for the first time, a pesky Thursday night game in Europe's lesser competition could complicate everyone's calculations. Should Pardew pick his strongest team against Bordeaux, or save it for Manchester United? Were he to field a weakened team, would a poor result in the Europa League set the wrong tone for the league match on Sunday? It's a tricky one and Ferguson will at least be pleased he got his European business out of the way on Tuesday, and collected three points. Over to you, Mr Pardew.