The 23-year-old was left out of the team in a friendly with Frankfurt on Saturday, as he closes in on a move away.
Ajax manager, Erik ten Hag, also admitted that the move was linked to developments over the player’s future.
Van de Beek had been linked with a move to Barcelona in recent weeks to link up with his former national team coach, Ronald Koeman.
However, it is now believed that a move to Spain is not an option, with United ahead of every other team.
The energetic box-to-box midfielder was close to joining Real Madrid in the summer of 2019.