Chile boss Jorge Sampaoli has told his side their World Cup bid starts against England at Wembley on Friday.
Sampaoli's men qualified for Brazil 2014 after beating Ecuador last month and play the tournament hosts next week as they continue their preparations for next summer's showpiece tournament.
"These next two friendly games, against top world sides like Brazil and England, will give us an idea of where we are and how we're going to compete in the World Cup," Sampaoli said. "They are very, very important.
"We know those two sides are going to give us a real stiff test. Any mistakes you make, they don't let you off. For me, the World Cup starts on Friday.
"England are always considered one of the top sides in the world in the FIFA rankings and are particularly strong when they play at home.
"Irrespective what the line-up is, it's important we treat it like it's the World Cup. It's a competitive match for us."
While Roy Hodgson's side drew criticism during a laboured campaign that finally ended with a flourish, Sampaoli is an admirer of their attacking options - and admitted his team would look to play on the break.
"We know that it's a challenge for us, but we've got to try to impose our style of play on the game," he added.
"We will try to take advantage of the breakdowns in play, the transitions in play and try to attack on the counter.
"The manager has got them quite disciplined and they're a strong unit defensively and keep things tight. At the same time, any breakdowns in play on the counter they're very, very quick to break out.
"When you've got (Danny) Welbeck fit and with the likes of (Wayne) Rooney and (Daniel) Sturridge, they create lots of problems and can make life very complicated for opposition defenders.
"They're a good side with a good chance (at the World Cup). What they've got to do is make sure they create enough of a goal threat to cement those good chances.
"They are a team that will get stronger during a tournament. They will get better and better as they progress."