Concise News learned that Hag acknowledges his players are attracting a lot of interest from other clubs.
However, Ajax has sold some of its top players which include, 22-year-old midfielder Frankie de Jong to FC Barcelona in a deal worth 86 million euros (75.18 million pounds).
Also, his teammate, 19-year-old Matthijs de Ligt is supposed to leave the club for another big club this summer.
Some of the other players like Hakim Ziyech, David Neres, Donny van de Beek and goalkeeper Andre Onana could also join the league of players to join Europe’s biggest clubs.
“To say I fear the transfer window is not the right word, but our players are hot right now,” Ten Hag told reporters.
“We left a very positive impression and that is a compliment for Ajax. It will be a heated summer. That (is something) we have to expect.
“But the club’s leadership and I are of the same opinion that we must have the potential to try and achieve again what we did this season.”
An estimated 60,000 supporters gathered on Amsterdam’s Museum Square on Thursday to celebrate Ajax’s domestic league and cup double.
The double was completed when they beat De Graafschap 4-1 on Wednesday to finish three points clear at the top of the Dutch league.
“It was an incredible season and we must continue in the same way. The enemy never sleeps.”
“To become league champions again will be our ambition. But in Europe? I cannot say right now. That we can only determine on Sept. 1, when we know what our squad looks like.”