Manchester United have three wins and three clean sheets from their last four games, and if one overlooks the fact that two of the clean sheets were against Cambridge United in the FA Cup it could be argued Louis van Gaal is finally getting to grips with his defence and his system.

A better test will come this afternoon at the Boleyn Ground, where West Ham and their high-ball game – Van Gaal’s own description after his side survived Wayne Rooney’s dismissal to win 2-1 at Old Trafford in September – will give the visiting back four a pummelling.

If it is a back four, that is. Van Gaal previously appeared wedded to a back three and wing-backs, but since complaining about 4-4-2 making his ass twitch he has enjoyed some success, albeit against bottom-three or lower-league sides, with four at the back and a diamond in midfield.

One thing the United manager is wedded to is Rooney playing a wide role in that diamond, as opposed to appearing at the tip in a more familiar attacking position. With a wealth of strikers at his disposal Van Gaal has converted Rooney into a midfielder; he even admitted this week that his captain was keeping Ander Herrera out of the team. The country’s most infrequently glimpsed £29m signing has more experience of playing in midfield, but Rooney is captain, Van Gaal argues, so must play. And if he cannot find a place up front, he must occupy one in midfield.

Sir Alex Ferguson tried the same thing, of course, and Rooney could scarcely conceal his displeasure. David Moyes put him back up front, with mixed results, but Van Gaal seems to have convinced him that midfield is the future. So Rooney returns to the ground where he scored a stunning goal from just beyond halfway last season with a brief to station himself around halfway, and according to his manager he is quite happy about it.

“I communicate with him, and give him my arguments about why he has to play there, and he accepts that as captain he has to do something for the team,” Van Gaal said. “I don’t think I have ever heard him complain about it, in fact I think he likes playing in midfield because he is more on the ball. So he enjoys it more. I would not say he will always be a midfielder from now on because it depends on the formation we use and the form of the strikers, but in the present system I need a right-footed midfield player.

“Not so many players can easily switch positions but Rooney can, he is multi-functional. He does not like switching positions within a game; I moved him from midfield to striker once and he was not so good, but he can definitely play in more than one position. I have come across such exceptional players before. Edgar Davids was an extreme left-winger and I made him a midfielder. Michael Reiziger was a No10 who became a full-back and Frank Rijkaard was a No6 who played as a centre-half in my winning team at Ajax. I always look at the qualities of the player and decide where he can perform better for himself.”

It is perhaps as well Van Gaal is not short of confidence and conviction, because many United supporters are not yet prepared to accept Rooney’s striking days are over. Play Rooney up front has been an insistent plea recorded on many message board threads these last few weeks, even though he now has Robin van Persie, Ángel Di María, Radamel Falcao and Juan Mata ahead of him in a literal sense, if not in terms of striking ability.

“What I keep saying to Wayne is that your contribution for the team is bigger when you play at right half,” Van Gaal explained. “You can cross the ball and pass the ball better from the right, and you can play in Antonio Valencia on overlaps. Talented players can usually play in different positions, but they don’t always like being played anywhere, so I have to take care of that. But I like multi-functional players because then you can vary your team more and become more unpredictable for opponents. We have Rooney, Di María, Mata and Adnan Januzaj who can switch around. That gives us an advantage, but you sometimes see Arsenal and Chelsea doing the same.”