Manchester United need to have the greatest transfer window of all time

The season's over, but the fun's just beginning: Louis van Gaal and Ed Woodward are taking care of business. Memphis Depay has already signed up, while Radamel Falcao is on his way back to France with a resounding "thanks, but no thanks" ringing in his handsome ears. And speaking after Sunday's bleak nil-all draw with Hull City, Van Gaal indicated that the wheels are already in motion:

I have talked with every player I think I have to talk to. I know which players have to go and which have to come.

We can have a reasonable guess at the players who will leave and, with the exception of David de Gea (and Rafael! Not Rafael? Poor Rafael), none of those departures are likely to weaken United. The focus, therefore, is on who's coming in. And looking at the squad, it doesn't seem unreasonable to conclude that United need half a new team. Specifically:

• a goalkeeper (given the likely departure of De Gea and in the event that Víctor Valdés isn't the answer, though he might be, at least for a season);

• a rightback (given the likely departure of Rafael and the shortcomings of Antonio Valencia);

• a central defender (given the likely departure of Jonny Evans, the youth of Paddy McNair and Tyler Blackett, the general shonkiness of Phil Jones and the less-pronounced but still occasional shonkiness of Chris Smalling and Marcos Rojo);

• a controlling midfielder (because even if you think Michael Carrick is the best midfielder in the world, he's getting on a bit, and Van Gaal has indicated he's after a "No. 6"); and

• a gamebreaking attacking player, either central or wide (given the departure of Radamel Falcao, the possible departure of Ángel di Maria, the increasing irrelevance of Robin van Persie, the youth of James Wilson and Memphis Depay, and the ongoing mystery of Wayne Rooney and the Best Position).

That's a lot of business. The names in the frame are mostly exciting and the pockets are apparently deep, but that's five new players, possibly six. And at least two of those, the goalkeeper at one end and the goalscorer at the other, need to be able to drop straight into the first team at the beginning of the season: United have an okayish defence and midfield, but an early crisis at either end could kill next season before it really gets going. The others perhaps have a bit more time, but all — except maybe Depay, who is very much a prospect — need to be established by the end.

The problem is that even with the best scouting in the world — and it's an open question whether United have that — transfers are incredibly difficult to get right. By almost any measure, the purchase of Di María last summer was a no-brainer: he was expensive, yes, but he had been consistently brilliant in both Spain and the Champions League, he'd had a great World Cup, and his style seemed ideal for the Premier League.

Yet here we are, eight months later, and whenever he steps onto the pitch he looks like a trembling, malcoordinated child. Maybe it was the burglary; maybe his heart's in Paris. Maybe Van Gaal broke him. But that's it: there's always the possibility of something going wrong, because something goes wrong so often. Every transfer is a risk, and some of those risks must fail. Or at least, take some time to succeed.

Chances are that even if United nail each of their first-choice targets, whoever they might be, things are going to go wrong. One will need time to adjust, another will need to learn the language, a third will find out that Louis van Gaal's ideas on trainer-coaching aren't quite what they're used to. That's just the transfer market. That's just life. People are fragile things.

Look at any summer of United business and you'll see exactly this: some obvious successes, some total toss, and an awful lot that fall somewhere in between the two. Over the last twenty years there have only been a couple of summers that United have done nothing but immediately good business: 2005, when Edwin van der Sar and Park Ji-Sung arrived, and 1998, when Jaap Stam and Dwight Yorke arrived and went straight into the team, while Jesper Blomqvist reinforced the bench. And on both occasions, that was about addressing one or two positions. Tweaking an already excellent squad, not rebuilding a profoundly patchy one.

In short, if United are serious about challenging Chelsea for the next Premier League and making inroads into Europe, they don't just need a good summer. They need what would be a near-unprecedentedly good summer. They need one of the great transfer windows; a kind of summer Ed Woodward will be telling his grandchildren about for years to come. Five or six successful signings, all established by the end of the season. That is an extraordinarily big ask of anybody, let alone an executive vice-chairman with just one summer under his belt.

Still, take heart, Louis, Ed, for it's not impossible. Not quite. In the summer of 2004, as Chelsea prepared for Jose Mourinho's first season in charge, they brought in eight players. Two were flops: Mateja Kezman, who played plenty but scored very few, and Nuno Morais, who only started one game. That's fine. There are always flops.

The other six, though: Paolo Ferreira, Petr Čech, Arjen Robben, Didier Drogba, Tiago and Ricardo Carvalho. All went on to have excellent, crucial seasons; all won the league by some distance; all went on to have Chelsea careers ranging somewhere between competent to brilliant. The idea of "doing a Chelsea" has all manner of unpleasant connotations. But in this instance, it might be just the thing.