Mauricio Pochettino has admitted Tottenham are "starting to be concerned" about Erik Lamela's mystery hip injury.
The Argentina playmaker will undergo a scan on Friday on the injury that has kept him sidelined since October - and that is yet to be diagnosed.
Lamela has been working with a physiotherapist at former club Roma in a bid to ease the problem, but Spurs boss Pochettino admitted it is now becoming a real worry.
"Tomorrow he will have a scan," said Pochettino.
"It's still difficult to give a time for him to come back.