The Dutch will yet again change their formation as Van Gaal has admitted he will field a 4-4-2 in their final match prior to their World Cup opener against Spain
Louis van Gaal - going into his final competition as Holland coach before making the move to Manchester United - will demand an improved effort from his side after their 1-1 draw against Ecuador was followed by a narrow 1-0 triumph over Ghana.
Ahead of June 13's Group B opener against world champions Spain, Van Gaal has one game remaining to assess his side and he will hope some of his players take the opportunity to get closer to their best form.
Van Gaal named an experienced 23-man party for the Brazil showpiece on Saturday, which included seven members of the squad from their run to the 2010 World Cup final.
However, he was left frustrated by their showing against Ghana later that day, describing his players' performance with the ball as "careless" as the Dutch missed a host of second-half chances.
Captain Robin van Persie has scored six goals in his last six games for club and country, including one each against Ecuador and Ghana.
However, Van Gaal suggested Van Persie may benefit further from doing less chasing up front while also admitting they will be lining up in a 4-4-2 formation, rather than a usual 5-3-2.
"If Wales play with a striker, it is pointless to play three [central] defenders... so it is 4-4-2," he said on Monday.
"What is important is that Van Persie does not do too much work. On Saturday against Ghana, Robin did too much. He was behind the right-back too often, and at times with the left-back.
"It's a little better each day with us, I think, but will that be enough against Spain, Australia and Chile? I do not know.
"If you look at the results in practice matches, we do not do bad."
Van Gaal will be without Jonathan de Guzman for Wednesday's game due to a hamstring complaint.
In their final game on home soil before flying out to Brazil, Netherlands welcome an opponent who they have dominated in recent times.
Wales, who will be without Real Madrid's Gareth Bale and Arsenal's Aaron Ramsey, have shipped 13 goals to Netherlands, including a 7-1 hammering in 1996.
However, they go into Wednesday's clash in reasonable form - unbeaten in four and off the back of a 3-1 win over Iceland in March.
While Chris Coleman's men are not involved in World Cup action, they will use the fixture as a warm-up for their first Euro 2016 qualifier against Andorra in September.
Chris Gunter is confident Wales can ask questions of the Dutch, even without Bale and Ramsey.
"Both sides have their own agendas. Netherlands will be fine-tuning for the World Cup in the summer, but for us, this is a vitally important game with a view to the Euro Championship matches that start in September," he explained.
"Even with Gareth and Ramsey missing we still have a strong squad and I am certain that we will give the Dutch a good game."