Manchester United are interested in Ajax's Netherlands midfielder Donny van de Beek.
The 23-year-old was left out of the Ajax squad for Saturday's friendly against Eintracht Frankfurt.
Coach Erik ten Hag said "developments" regarding his future had kept him out of the game.
Van de Beek, who has been capped 10 times by the Netherlands, was a key part of the Ajax side that reached the 2018-19 Champions League semi-finals.
United have yet to make a signing in the transfer window but could face competition from Barcelona, who have been heavily linked with Van de Beek having signed his former Ajax team-mate Frenkie de Jong last summer.
Ole Gunnar Solskjaer's side play their first game of the 2020-21 Premier League season at home to Crystal Palace on 19 September.