Even a showman of Cristiano Ronaldo’s capricious talents had had enough of terrorising opponents for one week. As Manchester United took a 3-1 lead at Villa Park on Saturday evening, ending Watford’s brave bid to resist the inevitable, the 22-year-old gestured to Sir Alex Ferguson that he wished to take a well-earned break just as soon as they scored their fourth.

As it transpired, he took his leave sooner, leaving his replacement, Kieran Richardson, to score the final goal of the game. Ronaldo rejoined his teammates on the pitch to celebrate with United’s joyous supporters at the final whistle, but by then their focus had already moved on to this week’s home matches against Sheffield United and Middlesbrough, to the Champions League semi-final against AC Milan and a showdown with Chelsea in the FA Cup Final.

There is simply no let-up for a team chasing success on three fronts. Ferguson often recalls how the decisive factor in their remarkable treble triumph in 1999 was that they had an empty treatment room and a full squad to choose from. At present it is difficult to see fortune smiling on them like that again, with Rio Ferdinand limping off in the first half on Saturday to become the fifth of their senior defenders to succumb to injury, but they continue to make light of such setbacks.

Ferdinand underwent a scan on a groin strain yesterday morning and the encouraging news is that he should be back for Saturday’s meeting with Middlesbrough or, failing that, the first leg against Milan a week tomorrow. Gary Neville might not be too far behind him in the comeback stakes, but this is not the time of season to have defenders dropping like flies. Ferguson suggested they were “down to the bare bones” defensively and, while a makeshift back four just about stood firm in the face of a characteristic aerial bombardment from Watford on Saturday, it is hardly ideal at a time when there is so much at stake.

Chelsea suffered a similar crisis of defensive personnel in the New Year and dropped the points that José Mourinho fears will cost them the Barclays Premiership title. But there is one significant difference between the champions and their heirs apparent.

Mourinho went into the season with six defenders, Ferguson with eight. The illusion of Chelsea’s strength in depth was exposed in that period in December and January, whereas Ferguson has seen players such as Wes Brown, Gabriel Heinze, John O’Shea, Darren Fletcher, Park Ji Sung and Alan Smith come into the United side to make telling contributions over the past weeks, Fletcher even filling in at right back after Ferdinand’s injury on Saturday. As Ferguson has suggested on several occasions, the efforts of their fringe players may prove the difference in the final reckoning.

Four goals or not, United looked like a tired team for periods on Saturday after their midweek exploits against AS Roma. A better side than Watford might have exploited that fatigue, particularly with Adrian Boothroyd having devised a strategy to unsettle them at setpieces, but their hopes were dented as early as the seventh minute, when Wayne Rooney stepped inside the challenge of Adrian Mariappa and beat Richard Lee with a stunning shot from the edge of the penalty area. So much for best-laid plans.

Briefly, that appeared to be it for Watford. Their supporters, already resigned to relegation, must have feared that United might match the seven goals they scored against Roma four days earlier, but Boothroyd’s team have plenty of fight. There was maybe a little too much fight for Edwin van der Sar’s liking, as the goalkeeper was jostled at a number of setpieces, but there was no doubting the quality of their equaliser, hooked in acrobatically by Hameur Bouazza in the 26th minute as United struggled to deal with Gavin Mahon’s long throw-in.

United’s reaction said much about their character as well as the quality that flows through their team. Smith, who again led the forward line well, sent Rooney clear down the right and the England forward bided his time before setting up Ronaldo for the kind of chance a player on a new £120,000-a-week contract dare not miss.

Again, Watford responded well and might have scored during a encouraging spell early in the second half, but Smith set up Rooney for the all-important third goal in the 66th minute, prompting Ronaldo to make his gesture to the bench. Richardson scored a well-taken fourth with eight minutes remaining, a fitting riposte to those United supporters who had jeered him on to the pitch, and that was it.

Each goal brought a delighted reaction from Ferguson and his coaching staff on the bench and also from Neville, who was sitting with his father in an executive box over one of the corner flags. The captain has been a frustrated spectator over the past weeks, since suffering a calf injury in the 4-1 victory over Bolton Wanderers, but nobody of a United persuasion could be miserable while watching football of the quality his teammates have produced at times over the past two matches.

This was nothing like the masterclass against Roma, more a case of United raising their game when they had to, but Rooney was outstanding. “I don’t want to rest. I want to keep playing in big matches,” the 21-year-old said on his way out of Villa Park. The coming weeks will give him every opportunity to do that.

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