Chile coach Jorge Sampaoli revealed that key midfielder Arturo Vidal is not guaranteed to face Spain in the World Cup Group B showdown between the teams Wednesday.
The Juventus midfielder underwent knee surgery a month ago and played for only the first 60 minutes of Chile's 3-1 win over Australia in their opening game Friday.
"I always said it was very difficult for him to join us here because he had a very serious injury and he had surgery," Sampaoli told a pre-match press conference in Rio de Janeiro on Tuesday.
"However, he managed to play some minutes against Australia and we'll see how he feels now. He's been training at a higher pace this week and we'll see if he can play some minutes tomorrow (Wednesday)."