When Manchester United are at their fluent attacking best Sir Alex Ferguson's players delight in confounding opponents by frequently, if temporarily, interchanging roles. Invariably wonderful to watch, such positional rotation is something only very good teams dare indulge in. Moreover their managers tend to ensure that these fluid interludes of movement are firmly underpinned by the reassuring presence of tactical safety nets.
Under enemy fire, leading sides usually revert to default starting formations with defenders deployed conventionally and even free spirits in the Wayne Rooney or Dimitar Berbatov moulds detailed to perform specific marking tasks. Yet as Ferguson prepares to celebrate his 70th birthday on Saturday he knows that so many pieces of United's basic framework have recently required patching up with ill‑fitting parts that he has little option but to improvise for entire 90-minute stretches.
With 11 senior players – including the long‑term absentees Nemanja Vidic and Darren Fletcher – occupying the Old Trafford treatment room the phrase "positional rotation" has assumed a whole new meaning as United's fit squad members are asked to pretend they are Ajax-type "total footballers".
If Michael Carrick and Patrice Evra cannot be described as exactly "ersatz" centre‑halves, the fact that Ferguson's team played much of their 5-0 Boxing Day thrashing of Wigan Athletic with the midfielder and the left-back paired at the heart of defence can only have warmed Roberto Mancini's heart. Even so, Manchester City's manager knows that a wounded United represents a most dangerous enemy. Since his side humiliated Ferguson's men 6-1 at Old Trafford in October, their neighbours have proceeded to win eight of the subsequent nine Premier League games, the last two 5-0.
Yet if fielding a talented winger such as Antonio Valenica at right-back and again promoting the hitherto unwanted Darron Gibson from the reserves to central midfield, clearly did not cramp United's style against Wigan, greater challenges await. The prospect of being without a cadre of key performers during a January programme featuring tricky league trips to Newcastle and Arsenal could conceivably cost United the title.
Pointing out that they now stand level on points with City at the top of the table, Evra takes a rather less gloomy view. Although Chris Smalling and Phil Jones may well recover in time to man the centre-half stations against Blackburn on Saturday, the France international is confident he and Carrick could, once again, prove able deputies.
"At United, the team is the star," says Evra. "That's why you can put me and Michael Carrick at centre-back and we're still going to win. It's about the team effort and the team spirit and that's why I'm confident. The United spirit is that you can play everywhere, in any position. No other side has United's spirit. That's why I'm so proud to play here."
There have been blips along the way but Evra now regards the Champions League exit to Basel as a disguised blessing. "It was a big disappointment when we went out early," he says. "But it was a wake-up call; maybe everyone looked at themselves in the mirror and said 'we can do much better'. What the fans expect of every player, we're all doing now. We're working hard. Nothing is easy but we have to keep our momentum going and trust each other."
If such endeavour is thrilling Ferguson, his side surely cannot keep on exceeding the sum of their currently out of position parts. "The injuries start to be annoying," acknowledges Evra. "We want everyone fit if we want to win the league." The fear inside Old Trafford is that history could be in recycling mode. With the manager's room for January transfer market manoeuvre presumably restricted by the gargantuan debt imposed on the club by the Glazer family, memories have been rewinding almost 14 years.
Despite at one stage enjoying an 11-point lead over Arsenal, a rash of injuries variously afflicting Peter Schmeichel, Gary Pallister, Roy Keane, Ryan Giggs and Nicky Butt in March 1998 saw Ferguson forced to ultimately concede the title to Arsène Wenger.
Coming second to Mancini would hurt more but the Glaswegian is often at his most innovative when backed into corners. "United can adapt to adversity," argues Roberto Martínez, Wigan's manager. "They have the mentality every other team wants. Anyone wanting to win the league has to better United's mentality."
