Arsenal's Alexis Sanchez injury doubt for Chile's clash against Brazil

Chile boss Jorge Sampaoli has revealed that Alexis Sanchez is a doubt for this week's 2018 World Cup qualifier against Brazil due to a knock.

The 26-year-old is in positive form after scoring twice in Arsenal's 3-0 victory over Manchester United at the Emirates last Sunday.

However, he might be forced to sit out of international fixtures against Brazil and Peru due to a knee injury, while Bayern Munich's Arturo Vidal also has a similar predicament.

"They are both in the same condition," Sampaoli said in a press conference. "I cannot confirm at this stage if either will be fit to face Brazil.

"Of course, they are very valuable to us but I am confident that if they are not available we have the squad to be competitive against Brazil or Peru."

Chile will face Brazil on Friday and Peru five days' later.