Louis van Gaal mischievously suggested he now has five strikers at his disposal as he prepares for Manchester United’s fifth-round FA Cup tie at Preston on Monday. All season long the manager has been talking of the four strikers in his squad, meaning James Wilson in addition to Robin van Persie, Radamel Falcao and Wayne Rooney, but not content with converting the last into a midfielder he now seems to want Marouane Fellaini rebranded as a front man.

“I am looking for different kinds of strikers and I hope you know I have five now,” Van Gaal said, making an oblique reference to Fellaini’s deployment as a target man at West Ham last week and the long-ball debate that ensued. Van Persie may miss the Deepdale game with an injury but the United manager was making the point that losing a striker does not necessarily mean a return to frontline duties for Rooney, not even in the week when Roy Hodgson said he would not be using him in midfield.

“He has to compare Rooney with the other available strikers in the same way that I do with mine,” Van Gaal explained. “England also might not need Rooney in midfield. I have to compare and decide where a player has to play to make the biggest contribution and, while I agree that maybe Rooney is better as a striker if I play him there, then I have a problem in midfield.”

That makes a certain amount of sense, except for a couple of considerations that appear to confound the managerial logic. The first is that the United midfield, with Rooney in it, was extremely ordinary in midweek against Burnley, when Van Gaal not only accepted his side had been outplayed in the first half but pointed to midfield as part of the problem. “We could not retain the ball or use it well enough,” he said. “Burnley played a good pressing game and we could not break out of the press.”

The second jarring note concerns the amount of money United have spent on midfield players in recent seasons. Ángel Di María, Juan Mata, Daley Blind, Ander Herrera and Fellaini have all arrived in the past 18 months at a cost of around £200m, to join highly rated performers such as Michael Carrick, Adnan Januzaj, Antonio Valencia and Ashley Young, who were already on the club’s books. Van Gaal needs only four of them to form a midfield, so it is somewhat puzzling that he looks at that list of talent and decides the answer must be Rooney, even if Carrick is currently injured. When Herrera finally got on to the field as a substitute against Burnley after making two starts in three months he did quite well. Many United fans simply cannot understand why a specialist midfielder has been on the bench for so long in favour of a converted striker who has not been playing badly but has hardly made a case for automatic selection as a midfield operator.Some critics even point out that Van Gaal has a record of switching players around, reinventing their roles and positions, in order to claim credit for himself when his apparent orthodoxy comes off. There may be something in that, but United spectators have not yet seen anything come off, despite the lofty league position. Even Van Gaal admits he is still searching for better balance, has not decided on his best system, and United are still a work in progress. They are also still in the FA Cup, though as the manager said in one of his more brutal assessments during a busy week, they will not be for much longer if they play as poorly against Preston as they did against Burnley.