Van Gaal, who has criticised the travel and commercial demands placed on his players in the US, also voiced his frustration at the state of the pitch at the Michigan Stadium, which is more commonly known as the 'Big House' as it is the third-biggest stadium in the world.
The new pitch inside the arena, which is used primarily for college gridiron, was only laid on Sunday, much to Van Gaal's dismay.
The United boss has been annoyed with the surfaces on this tour, which has taken them to Los Angeles, Washington DC and Denver before they came to Ann Arbor, which is on the outskirts of Detroit.
"The pitch is not good," Van Gaal said after a training session which was watched by club co-chairman Avram Glazer.
"They are used to American football here and that is throwing the ball with the hand so it doesn't take care of the ground, the pitch is not so good.
"It's a pity because we have fantastic teams but we have to play on bad pitches so the ball is not rolling (well). It is difficult."
Wayne Rooney, sitting alongside Van Gaal at the press conference, said the pitch was "very soft".
The England striker, who is in the running to be named captain under Van Gaal, is looking forward to a new era under the Dutchman following last year's disappointing seventh-place finish.