Dejan Kulusevski has undergone knee operation and will not play in the Europa League final.
It is the newest blow for Tottenham who are already without creative midfielders James Maddison and Lucas Bergvall for confrontation with Manchester United in Bilbao on Wednesday.
Maddison and Bergvall will no longer play this season and although Spurs has not specified a time frame for the absence of Kulusevski, his season is probably over.
The 25-year-old Sweden international was the best player in Tottenham at some distance during the first half of the season until February when a foot injury excluded him for six weeks.
Since then he has not recaptured the same form and has been selected to start against Palace, when the majority of the first team was equipped, hoping that it could help him find his rhythm again.
Kulusevski lasted only 19 minutes before he had to be replaced and although boss Ange Postecoglou said he was hopeful that it was nothing more than a knock, it turned out to be more serious.
Maddison damaged the knee ligament in the first stage of the semi-final of the Europa League against Bodo/shines and is expected to be out for three months. Bergvall has a single injured in training on the eve of the same game.
This is what Postecoglou leaves behind specialized midfielders. Rodrigo Bentancur, Yves Bissouma and Pape Matar Sarr are his senior options. Archie Gray, 19, will also be compared.