The Red Devils have only recruited two players since the Dutchman's arrival at Old Trafford but he is happy to see how their season starts before making quick deals
The Red Devils have so far only signed Ander Herrera and Luke Shaw this summer, despite their interest in the likes of Arturo Vidal, Mats Hummels and Angel Di Maria.
Goal understands that United are pushing hard to sign Juan Cuadrado and Daley Blind, though their move for Sporting Lisbon's Marcos Rojo has taken a twist through a dispute between his club and agents.
However, Van Gaal insists that there is still plenty of time to complete deals before the transfer window closes on September 1.
"I wanted to assess my team. I can judge only when I am the coach and I transfer my philosophy and know how they perform," the Dutchman told reporters on the eve of United's Premier League opener at home to Swansea City on Saturday.
"So that's what I am doing. I think that is honest. We have to wait and see because you can buy a player in 24 hours, believe me. That's not a problem."
Van Gaal also reiterated his calls for patience as he attempts to overhaul the club.
The former Netherlands boss has overseen a change of formation, with a 3-5-2 system adopted throughout an unbeaten pre-season, and though the summer has seen good results the 62-year-old warns that there could be hiccups along the way.
"I cannot change everything [straight away]," he added. "I have to adapt to the culture. It's a process and we have to make steps.
"Sometimes you fall and you have to make another big step. That's the process but you are not champion in October, you are champion in May. I have another philosophy. I have another way of dealing with players to normal coaches.
"I'm not concerned where we might be [if we have a slow start] and I've said that in my meetings with [Ed] Woodward and the Glazers."