Spurs signed the winger on an 18-month loan from Juventus in January last year with an obligation to buy the Swede for £31m if he played at least 20 Premier League games and the club qualified for the Champions League.
Tottenham finished eighth in the Premier League this season and do not have any European football to look forward to next term.
With Tottenham finishing outside the top fix, the obligation to buy Kulusevski has become an option.
Spurs are still planning to exercise the option to buy to sign the winger but they will not be paying the £31m fee.
Tottenham are now expected to get the deal over the line to sign the Swede for a slightly lower fee.
The winger has been non-committal on whether he wants to stay at Spurs but it has been claimed that the decision rests with the club.
It is expected to be a straightforward deal in a summer where Spurs are expected to be busy in the market.
