Kulusevski has been sidelined since May 2025 with a persistent patella knee injury that required surgery, followed by a setback that necessitated a further procedure.
The 26-year-old spoke positively ahead of Sweden's World Cup play-off victory over Poland — a 3-2 win under head coach Graham Potter that secured qualification — saying he was "100 per cent determined" to be fit in time. De Zerbi's assessment was more measured.
"I don't know the situation well. For me, it's difficult to understand how he can play at the World Cup if he didn't play any games this season. But I texted him after the Villa game. He told me he comes back next week, I think, to continue his rehab at Hotspur Way. And I hope he can be available to stay with us in the last game because he is an amazing player."
De Zerbi also confirmed Brazilian forward Richarlison's absence from training this week was due to fatigue rather than injury, following his goal and influential display in last weekend's 2-1 win over Aston Villa — a result that lifted Tottenham out of the relegation zone.
"Yes, he missed training because he worked very hard against Villa. My mistake was not to substitute him before the end of the game. But he was playing very well and important in set-pieces. Just fatigue."
Tottenham sit one point above West Ham United in the table with three matches remaining. Monday's home fixture against Leeds United could prove decisive in the survival fight. Leeds are battling for play-off promotion while Spurs need results across a series of increasingly pressured final-day scenarios.
Kulusevski has contributed 25 goals and 30 assists in 146 appearances for the club since joining from Juventus in 2022. He remains contracted until June 2028.