Di Maria this week joined the Red Devils in a British record £59.7 million (€75.1m) transfer from Real Madrid but the huge transfer has been overshadowed by United’s dismal start to the season.
United are yet to win a competitive game under Van Gaal and hit a low point on Tuesday when they were humiliated by League One MK Dons in the Capital One Cup.
Van Gaal’s tactics have come in for criticism but the Dutchman has stressed he needs time to reshape the squad in his image.
His squad redevelopment could be accelerated in the coming days with United — who have already spent £131.7m (€165.6m) this summer — linked with more players, notably Arturo Vidal of Juventus and Sporting Lisbon’s William Carvalho.
Some players could also leave before Monday’s transfer deadline with Javier Hernandez, Danny Welbeck, Shinji Kagawa and Tom Cleverley among those linked with moves.
Van Gaal, speaking at a press conference to unveil Di Maria, said: “I cannot say anything about that because it raises the price.
“The club shall comment when the time is there to announce it. We cannot react on every rumour.
“Also players shall go in the meantime. I had a conversation after lunch with the players and I said that maybe after this weekend we shall have another group because players shall go away and others shall come in.”
Di Maria, man of the match in last season’s Champions League final and a key performer for Argentina at the World Cup, is a highly-coveted player but questions have been asked of how he could fit in Van Gaal’s 3-5-2 system.
Van Gaal believes both the player and formation can be adapted to suit each other.
He said: “I only buy players that can improve our philosophy, so I have spoken already about his way of playing in the interests of the team. He can accelerate our play and our style of play but he fits in our philosophy.
“But I can change the system for him and maybe I shall do that in the future, maybe during a match.
“He played at Real Madrid not only as a wide wing player but also in midfield, so that is also a reason why we are convinced he shall succeed.”
Di Maria, who will be entrusted with United’s famous number seven shirt, is happy to play wherever he is asked.
He said: “It depends on the manager and where he wants to play me.
“I come here to work for the team and I am prepared to play in any position he wants to. I just want to help the club become successful again.”