Alexis Sanchez is set to miss Chile's Confederations Cup opener against Cameroon on Sunday, although the Copa America winners will give the Arsenal star every opportunity to recover from an ankle injury.
Sanchez skipped training prior to the clash with the African champions in Moscow and is unlikely to start Chile's first game of the tournament.
Coach Juan Antonio Pizzi said: "Alexis had some health troubles a couple of days ago and, on Friday, we decided we would let him rest.
"We will introduce him slowly so he can maybe join us later. He's still recovering, he's maybe not ready yet but we will wait until Sunday to see what's best for him and what's best for the team considering it’s the first game."
Pushed further on the extent of the injury, Pizzi added: "He's had some problems with his left ankle, and it's the same leg where he had the injury during the Copa America. One injury was an external injury, this one is internal.
Chile also have concerns over goalkeeper Claudio Bravo, whose torrid first season at Manchester City ended with him being carried off on a stretcher after sustaining a calf injury against Manchester United on April 27.
He is with the squad in Russia but is also likely to sit out La Roja's opener with Johnny Herrera set to deputise.
Pizzi said: "We are of course happy that Claudio's making such an effort to be here and at our disposal and, depending on his recovery, we will decide whether he will play or not.
"I don't know when he will be available but I feel quite happy that he's recovering.
"On Friday he was on the pitch and said he felt much better so we will see."
If Bravo is ruled out, Pizzi has no concerns over 36-year-old Herrera, adding: "I don't like comparisons, every player has strengths and weaknesses so I think it's important to recognise all of them are professional.
"I trust them, that's why they are here. I don't ask players to join up because I feel like it. I trust them and value them so that's why I feel confident about them.
"I trust Johnny. I am very relaxed and not worried at all."