Alexis Sanchez could miss up to three months with an ankle injury, according to Chile manager Reinaldo Rueda.
The Inter Milan forward - on loan from Manchester United - sustained the injury during the second half of Chile's goalless draw with Colombia on Saturday.
The Chile Football Federation said Sanchez had "dislocated tendons" in his left ankle.
"He could end up under the knife," Rueda told a news conference.
"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 and scored two goals, while also playing in the Champions League.
"He was happy and super motivated. Now we have to wait for these decisive hours."
Sanchez joined Antonio Conte's side on a season-long loan in August and has scored once for Inter in four appearances, receiving a red card in the same game against Sampdoria last month.