The German club signed the Manchester City defender on loan last summer and Itakura played a major role in getting them promoted back to the Bundesliga.
Schalke have an option to make the move permanent this summer but that clause in the loan agreement expires today.
They would have to pay a fee of €6m to get the deal over the line but that is beyond their budget for the summer without sales.
And as such it appears Itakura will be looking for a new club in the summer.
Schalke’s financial limitations mean the Japanese defender’s other suitors will come into play in the upcoming transfer window.
Ange Postecoglou is interested in the player and wants to take him to Celtic in the coming months.
But they are facing competition from clubs in the Premier League as well as Germany this summer.
Fulham and Bournemouth have their eyes on him following promotion to the Premier League, and Eintracht Frankfurt and Hoffenheim are his German suitors.
