Arsenal star Alexis a doubt for Chile

Chile may be without Arsenal forward Alexis Sanchez when they begin their World Cup 2018 qualifying campaign against Brazil, according to Jorge Sampaoli.

It is also thought that Bayern Munich midfielder Arturo Vidal may also be missing for Sampaoli's side.

Both Sanchez (knee) and Vidal (groin) have been included in the Argentine coach's squad but have arrived carrying knocks picked up on club duty.

And while Sampaoli remains unsure if either of them will be able to feature in the recently crowned Copa America champions' opening clash with Brazil, he still feels they have the quality to begin their campaign in a successful manner.

"They are both in the same condition. I cannot confirm at this stage if either will be fit to face Brazil," the 55-year-old said in a news conference.

"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."

Dunga's side suffered a quarter-final elimination from the 2015 Copa America at the hands of Paraguay, but Sampaoli still believes they pose a significant threat.

"Starting the qualifiers against Brazil is the worst possible scenario," Sampaoli said.

"They are still the greatest power in the world, despite all the criticism, and they have elite players.

"Starting against Brazil or Argentina is much riskier than playing other teams."