The Ecuador midfielder underwent surgery on his fractured left ankle on Wednesday night.
The 25-year-old suffered suffered a clean break of the tibia and fibula, rather than a compound fracture, during the Champions League draw against Rangers on Tuesday.
Ecuador national team doctor Hector Bohorquez said: “In the case of a dislocation, ‘Tono’ could have been back within two months, but a fracture means he faces four to six months away from the pitch.
“It is important that immediate surgical care is received in these cases. The player must then be supported continuously.”
