The 24-year-old plays his club football in Spain and expects la Roja to provide his nation with a stern test next summer
Chile, who have been tipped by many to be a surprise package at next summer's tournament in Brazil, will also face the Netherlands and Australia in their quest to advance from a tough group.
"Right now I would take us finishing second in the group and Spain winning it," the winger admitted to AS.
"It's hard to say who is the favourite, it's the most difficult group of all. I hope everything goes well for us. Our attitude has always been the same, when we begin to become desperate, that's when things go wrong for us."
Spain coach Vicente del Bosque highlighted Chile as one of the nations he wanted to avoid prior to being named in the same group as the South American nation and Sanchez is delighted the progress of the national side is now being acknowledged.
The 24-year-old added: "It's great that Spain have so much respect for us, as they are the world champions."
Juventus midfielder Arturo Vidal then echoed Sanchez's sentiments in outlining the obstacles in Chile's path, but remained upbeat over his side's chances.
"It's a difficult group, but there's still a long way to go to prepare for the World Cup. We know it will be a very difficult group, but I think we have a good enough team to get through."