Van Gaal is isolating in Woudschoten after returning a positive test on Tuesday.
Danny Blind, Henk Fraser and Frans Hoek will take on Van Gaal's duties until the Oranje boss is able to link up with the squad again.
Netherlands faces Denmark at the Johan Cruijff ArenA on Sunday (AEDT) and takes on Germany in Amsterdam three days later.
PSV defender Jordan Teze was last week called up for the upcoming friendlies and is poised to make his debut.
The Oranje qualified for the World Cup in Qatar this year by winning Group G with a 2-0 win over Norway in November.