Alexis Sanchez could face a lengthy spell on the sidelines with an ankle injury, Chile coach Reinaldo Rueda has said.
He was released by Chile to return to Inter for treatment, with the country's football association referring to "dislocated tendons".
Rueda has now said that the problem could require surgery.
"He could end up under the knife," said Rueda at a press conference widely reported. "Inter, his club, will decide.
"We could lose him for two or three months. It's a shame because he had started playing again with Inter."
Sanchez, 30, moved to Italy on a season-long loan after failing to impress at Old Trafford.
He has scored once for Inter in four appearances, as well as receiving a red card – both in the same game against Sampdoria.