Van Gaal was officially unveiled to the media on July 17, following his commitments with the Netherlands at the World Cup in Brazil, and he has hit the ground running at United.
The Dutchman has introduced a new 3-5-2 formation - based on a three-man defence with two wing backs - and overseen three consecutive wins over the Los Angeles Galaxy, Roma and Inter in the United States.
While Van Gaal recently admitted United will struggle for the first three months as they attempt to adapt to a change of system, Mata said the early signs have been promising ahead of Saturday's International Champions cup clash with Real Madrid in Michigan.
"The manager's new system could be very good for us," Mata told United's official website.
"Obviously we need to train more and improve but I think it's very difficult for opponents when we play like this. For me personally, playing behind two strikers is a great position to help me perform at my best level.
"The first thing the manager told us in pre-season training was that the first three months of this season would be hard, because we had to change our mindsets and understand what he was trying to do, and there was a new system as well."
Mata added: "It will take time to fully adapt but, in the meantime, we are doing our best.
"We're enjoying training and the most important thing is that we are learning from him, because he is a very experienced coach."
United open their Premier League campaign against Swansea City at Old Trafford on August 16.