The magnitude of Spain's opening 5-1 World Cup loss to the Netherlands comes into sharper focus Wednesday when the defending champions must fend off elimination against Chile, less than a week into the tournament.

Spain and 2010 runner-up Netherlands were expected to advance from Group B, but plenty of pundits — including Brazilian great Pelé — tipped Chile as a genuine contender to progress at the expense of one of the European powers.

The Chileans opened with a 3-1 win over Australia, and a second straight victory by the South Americans almost certainly would knock Spain out of the competition.

Meanwhile, the Dutch play Australia, the lowest-ranked team in the tournament, in the first of Wednesday's three matches. That is followed by Spain vs. Chile and the Group A match between Croatia and Cameroon.

Things to watch for Wednesday:

Spain coach Vicente del Bosque stuck with the core group of players who have helped deliver two European championships and a World Cup in a tremendous streak starting in 2008. But after their humiliating loss to the Netherlands, he has forecast changes. Spain needs at least a draw against Chile to remain in contention.

There's speculation that Cesc Fabregas could replace Diego Costa and Pedro Rodríguez could come in for David Silva. Captain and goalkeeper Iker Casillas' spot is also under close scrutiny.

"In life, there are solutions for everything," del Bosque said. "It's still in our hands."

Chile hasn't beaten Spain in 10 tries.

"A draw is not bad, but this group of players does not come with the idea to draw a game," Chilean midfielder Marcelo Díaz said. "We came out with the idea of winning."

Big games by Arturo Vidal and Barcelona forward Alexis Sánchez are crucial to Chile's chances. Vidal, the creative midfielder who plays for Juventus, is recovering after knee surgery and played for an hour against Australia.

Both Cameroon and Croatia are looking to bounce back from defeats, with Cameroon losing 1-0 to Mexico, and Croatia enduring a 3-1 loss to Brazil in the tournament's opening match. It appears Croatia has come out of defeat in better shape than its African rival.

Chelsea striker Samuel Eto'o had a brace on his right knee as the Cameroon squad left its training base to travel to Manaus and already has posted on social media that he's unlikely to play.

Losing their captain is a big setback for Cameroon, which has won just one of its 13 World Cup games since reaching the quarterfinals in 1990.

Barcelona's Alex Song will have to take on extra responsibility in midfield, while Mainz forward Eric-Maxim Choupo-Moting is likely to cover for Eto'o and 22-year-old Lorient striker Vincent Aboubakar may get his chance at the World Cup.

Croatia playmaker and Real Madrid midfielder Luka Modric is expected to recover from a foot injury and take the field against Cameroon.

The Croatians were furious about a penalty awarded to Brazil in their opening match, which allowed the home team to take the momentum, and are desperate to put that behind them.

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