Matthijs de Ligt will move to one of the world's top six clubs, according to Ajax director of football Marc Overmars.
Centre-back De Ligt has helped Ajax reach the last 16 of the Champions League, with the Dutch giants hoping to overturn their 2-1 deficit in Tuesday's second leg away to Real Madrid.
The Netherlands international is already the captain of his club at the age of just 19 and has been linked with clubs including Barcelona and Manchester City.
Barca have already snapped up De Ligt's team-mate Frenkie de Jong, who will join the club for the 2019-20 season after signing a deal worth a total €86million.
Overmars played for both Ajax and Barca during his career and he accepts De Ligt will soon be moving on from the Eredivisie side as he himself did.
"For me, De Ligt can play easily for any of the six best teams in the world," Overmars said to AS. "Right now. He has the power, the mentality. He has a heart.
"If I worked at another club, I would like to sign him immediately. We do not need to sell, we do not need the money, why be too rich, but...I know he will go to one of the big ones."
Overmars admits the club will likely face a rebuilding job at the end of the season with De Ligt following De Jong out of Ajax.
"We do not want to [sell players], but we have no choice," he added. "My job is to make a top team, but we cannot keep players like Madrid or Barcelona, who can have [former Ajax goalkeeper Jasper] Cillessen four years on the bench.
"If a player here spends a lot of time on the bench...they come to Ajax to be seen. Two years ago we played the final of the Europa League [against Manchester United] and rebuilt again because we lost players. In two years we have achieved it. When we arrived there was no money, we had to generate it.
"The world has changed a lot with the young players. I need to be faster than the other clubs."
Overmars has also been linked with a move away from Ajax. He is reportedly on Arsenal's shortlist to become their new director of football.