Tottenham fear summer signing Giovani Lo Celso has suffered a serious injury on international duty.
Lo Celso returned to Spurs early following a blow to his left groin in Argentina's 0-0 draw with neighbours Chile on Thursday and he is being assessed by the club's medical staff.
The playmaker insisted after the game that his injury was "not something to worry about" but the initial prognosis has left the club concerned that he could be sidelined for several weeks, starting with Saturday's home match against Crystal Palace.
Pochettino this week described the 23-year-old as an "incredible boy", telling Argentine radio: "He is a great footballer, he only needs time to adapt."
A serious injury to Lo Celso would be a frustrating setback for the midfielder and the club.
Spurs hope to welcome back both players, as well as Juan Foyth and Kyle Walker-Peters after the international break, with their first Champions League group game at Olympiacos a week today.