The Juventus midfielder Arturo Vidal is Manchester United’s top midfield target but the club’s concerns about his fitness are so great that it may require a complex, appearance-based contract if he is to follow Angel Di Maria into Louis van Gaal’s squad, taking the two-year transfer spend at Old Trafford crashing through the £200m barrier. After a summer in which United have persistently felt that Juventus have been seeking to manufacture a market for the Chilean – with a £34m asking price they have always considered too high – the desperate need for midfield protection has led to a softening of their tone where the prospect of doing business with the Turin club is concerned.