In hindsight, you wonder whether a part of Wayne Rooney no longer finds the idea behind that Nike advert so amusing. You know the one: an overweight Rooney, with a white vest and a mangy beard, living in a caravan, peering out behind greying net curtains. This is what could happen, we were told, if he messed up at the World Cup.

The alternative was Rooney returning from South Africa with a medal round his neck and, nine months on, England going through a boom of new babies by the name of Wayne. Then the tournament started and it became apparent that the vibrant Rooney, the player of breathtaking boldness who scored 34 times for Manchester United last season and accumulated all the player of the year awards, was not going to meet the challenge. Lionised beforehand, lampooned afterwards, Rooney has been through the full spectrum when it comes to the blame culture and knee-jerk reactions of modern football.

All sorts of theories have been offered up in the passing weeks. The most plausible is that England's hugely gifted striker was struggling for fitness while the most disconcerting, for someone who wants to be remembered as a football great rather than merely a great footballer, is that it was the first time in his professional life when the weight of expectation was simply too much.

Even Sir Alex Ferguson, his manager at United and a staunch protector of his own, concluded that the pressure may have got to his player. He would be better in Brazil next time, Ferguson promised. Yet the explanation was contradictory in the extreme. Ferguson went from saying there were no issues about Rooney's fitness – the striker has not scored since damaging an ankle in March – to arguing that England's problem stemmed from the main players being worn out.

What can be said with certainty is that Rooney will be relishing the thought of going back out on a football pitch, rather than spending any more time mulling over what went wrong and those statistics that tell us he was tackled 8.25 times per game (more than any other player) and that he has now had 22 shots in World Cups without scoring.

His first match is in Dublin tonight, when Ferguson's team will mark the opening of the Aviva stadium by taking on an Airtricity League XI. Rooney returned to training only last Wednesday, and it may be a brief appearance. He has not spoken publicly about the World Cup yet, and don't expect him to be too forthcoming on this occasion either. The photographs of him leaving the Panacea bar in the early hours of Sunday, looking more like one of the Gallaghers than a professional sportsman, have made sure it could be some time before we get any detailed insight into why he thinks it all went so wrong.

Panacea, for those unacquainted with Manchester's nightlife, is the establishment favoured by North-west footballers, the nouveaux riches, assorted wannabes and never-will-bes. It is a tawdry place where the clientele seem to be under the misapprehension that drinking champagne is a symbol of class, and it is easy to imagine Ferguson's reaction upon seeing his best player chugging on a cigarette (in mitigation, he does not look like a natural smoker), appearing to urinate behind a dustbin or bouncing down the street, chanting football songs. It was bright daylight – 5.30am – and it could be the scene from a scene of Ibiza Uncovered. Everything we know about Ferguson tells us he will be livid.

In fairness to Rooney, such moments are the exception rather than the norm these days, and there are plenty of other footballers at Old Trafford on better terms with the city's doormen. Anderson is more of a concern for United's management, and it has not gone unnoticed that the Brazilian's car crash in Portugal last weekend, when he was fortunate to escape more serious injuries after being pulled from the smouldering wreckage, occurred at 7.30am, after leaving a nightclub.

Ferguson almost always keeps disciplinary matters in-house, but it is safe to say there has been little sympathy for Anderson at his place of employment. "Let's hope it has knocked some sense into him" has been a standard quote.

As for Rooney, Ferguson has said the challenge for him is to improve again from last season and it should help that the club have recruited a potential new partner, Javier Hernández, a largely unheralded signing when the announcement was made last April but someone who demonstrated at the World Cup that United's scouts may have discovered a player of class and achievement. His signing was necessary because Rooney's partnership with Dimitar Berbatov has flickered without igniting, whereas Ferguson has seemed strangely reluctant to pair him with Michael Owen.

Ferguson seems to believe the disappointments of the summer will help Rooney's development. Above all, he is hoping the media now realise it was wrong to put so much faith in one player, albeit one United's fans serenade as "the white Pele". The likelihood, after all, is that, come the spring of 2015, England's maternity wards won't be filled with baby Waynes either but Rooney, still only 24, does have age on his side – and he will still be the player whose presence makes spectators quicken their step on the way to the old Lansdowne Road tonight.