The Dutch have enjoyed a flawless start to their Group D campaign, with victories over Turkey, Hungary, Andorra and Romania in their opening four fixtures.
Van Gaal's men are three points clear at the top of the standings and will face off against an Estonia side that have lost three of their four matches, with their sole victory over group minnows Andorra.
But former Ajax, Barcelona and Bayern Munich coach Van Gaal is refusing to believe the eastern Europeans will be a pushover.
"The expectations will be high, the audience will probably have a score of 5-0 in their head," he told a press conference.
"But that is just more difficult, especially given that the system Estonia play, with two rows of four and just one striker."
Van Gaal is likely to include Wesley Sneijder in his starting XI after the playmaker missed the last four Holland games due to injury and lack of match fitness, having been frozen out by former club Inter Milan.
The 28-year-old's move to Turkish outfit Galatasaray in January has given him a new lease of life and his return will be a welcome one.
The group leaders are without Tim Krul due to ankle problem and Klaas Jan Huntelaar (knee) although Maarten Stekelenburg is the probable option between the posts after missing Holland's last two matches with an injury.
Hungary and Romania, both on nine points, are contesting a play-off spot although they will be hoping to keep the pressure on the Dutch when they clash at an empty Ferenc Puskas Stadium in Budapest.
The Court of Arbitration for Sport last week rejected an appeal from the Hungarian Football Federation against having to play against Romania behind closed doors for racist behaviour by fans.
FIFA's disciplinary committee found a group of Hungary supporters had chanted anti-Semitic abuse and displayed offensive symbols in their friendly against Israel in Budapest last August.
Hungary boss Sandor Egervari is in confident mood despite the fact they have been denied home support.
"Of course, we expect to win this 'six-point' game, especially because we meet a rival, which is also a chance to better our chances of finishing first or second in the group," he said at a press conference.
Friday's final group match sees Turkey travel to Andorra and visiting coach Abdullah Avci insists his side will not be underestimating the threat posed by Friday's hosts.
Andorra have won just one competitive match - against Macedonia at home in a 2006 World Cup qualifier - but Avci is not taking victory for granted.
"A Turkish national football team will follow the opponent extremely seriously," the Turkey boss told reporters.