Reports in the Netherlands suggest Van de Beek is nearing a move away from Ajax, with Manchester United, who have scouted him extensively, one of several interested parties, and that is why he did not take part in the warm-up match.
In May, Ajax chief executive Edwin van der Sar confirmed the midfielder will be allowed to leave, but only for a suitable fee.
Van de Beek was close to joining Real Madrid prior to the Coronavirus pandemic but he did not complete a medical or sign an agreement with the club.
It is understood Van de Beek will consider a move to the Premier League, but Ajax have yet to receive any formal offers from any club this summer.
United are one of several clubs monitoring the situation, with Van de Beek one potential option should they decide to bolster the ranks in midfield. Jadon Sancho, however, remains their number one target.