The aim is that his wonderful array of attacking players, Rooney included, will be the ones to win him games. But that's another stage of United's development. And they are not there yet.
For now, there are other players more important to success, and David De Gea is one of them. United's 11-game unbeaten run—eight of them wins—hasn't been achieved with flowing attacking football of which Rooney is a purveyor.
Instead, it has been done with grit and resistance, and no one has shown more of that in the last two months than United's goalkeeper. Van Gaal will hope that's not always the case. He would prefer that De Gea had nothing to do during games instead of being asked to praise another fantastic save in every post-match press conference.
However, he will know that his new-look team have not had enough time to jell. And until then, United's organisation will slip from time to time, and De Gea will be asked to bail his team out.
United certainly wouldn't be sat third in the Premier League table with 37 points had it not been for their Spanish stopper. Saves against Everton, Arsenal, Stoke City, Southampton, Liverpool and Aston Villa have all won points.
It's remarkable that, after all the criticism the defence has had and the shaky moments they have endured, United have still only conceded one more league goal than Manchester City and Chelsea. That has everything to do with De Gea.
It's likely that until Van Gaal can bring in a world-class centre-half and pick the same defence consistently, he'll be called on again and again. It's what makes losing him such a frightening prospect for the fans.
The 24-year-old is yet to sign an extension to his contract that will run out in 2016. His performances this season and last, plus the fact that he's on the verge of cementing his place as his national team's No. 1, will not have gone unnoticed in the board rooms of the biggest clubs in Spain.
Had you asked United fans what they wanted most for Christmas this year, most wouldn't have said an expensive new signing. They would have said they were hoping for news that De Gea is staying put.
There are similarities to be drawn with Cristiano Ronaldo's rise at Old Trafford.
Ronaldo was a young footballer who arrived in England with a lot to learn. He worked hard, filled out physically and became the best in the world.
De Gea's rise hasn't been quite so explosive, but the paths they've taken are not too dissimilar. Ronaldo, however, has ended up spending his peak years at Real Madrid. United fans will hope that's where the similarities end.
The supporters know better than most how hard it is to find a top-class goalkeeper. Peter Schmeichel left Old Trafford in 1999, but it wasn't until Edwin van der Sar was signed from Fulham six years later that they found an adequate replacement. Mark Bosnich, Massimo Taibi, Fabien Barthez, Tim Howard and Roy Carroll all tried to fill the void and failed.
It looked for a while like De Gea might fail in his bid to replace Van der Sar, but now the fans can't imagine life without him.
There will come a time when Rooney, Di Maria, Falcao and Van Persie are more important to United. It will be a time when Van Gaal's side are smashing through teams with an attacking edge as sharp as anyone in Europe.
The Dutchman will have more of his own players in the team and, with more time on the training pitch, have them better organised and "dominating" teams in line with his footballing "philosophy."
However, that time hasn't arrived yet. As a result, neither has De Gea's time out of the spotlight. He's central to United's success at the moment because of their obvious deficiencies.
There will be a time when Van Gaal will hope that's not the case and De Gea can stand and watch his talented team-mates win him games and trophies. But they're not there yet.
Quotes obtained first-hand.