Argentina coach Alejandro Sabella knows there will be no margin for error in their first knock-out match against Switzerland.

La Albiceleste reached the last-16 as Group F winners, although their victories over Bosnia, Iran and Nigeria were far from convincing.

The South Americans failed to reach their peak in any of those matches and Sabella knows that needs to change on Tuesday, when they take on Switzerland for a place in the quarter-finals.

"We know we have to be very focused and maintain balance," the Argentina coach said.

"Obviously at this stage there is no margin for error, in the group stage there is chance of a recovery.

"We have to be very focused. Errors become more and more expensive."

In truth, if it was not for Lionel Messi's inspired form then Argentina could have become one of the tournament's high-profile casualties.

The 27-year-old has previously failed to reach his potential on the world stage but has shone in Brazil, netting in all three matches so far.

Messi will again be key in Sao Paulo, with Sabella comparing him to Diego Maradona when Argentina last won the World Cup in 1986.

"Messi's playing an amazing World Cup, that's what everybody expected," he said.

"I expected it, so did his colleagues and so did all Argentinians in general. So of course we're happy, we're happy for the team and for him as well.

"He's an important player for us. Maradona was a very important player in that time and Messi is important as well."

Messi is one shy of Maradona's five-goal haul in 1986 and the bookmakers' favourite to be crowned player of the tournament.

Switzerland frontman Admir Mehmedi has not been caught up in the hype, though, knowing the clash at Corinthians Arena will be decided by more than just one man.

"Swap jerseys with Messi? I'm not here as a tourist," he said. "Switzerland is in the second round of a World Cup.

"With all due respect for his qualities and his class, I think too much is talked about just Messi.

"He is exceptional, no question, but that is not all, he has very good players around him. We will not neglect the preparation nor in the game itself."

Mehmedi preferred instead to single out Angel di Maria for praise, before speaking up Switzerland's chances of causing an upset in Sao Paulo.

"I know the quality and potential of this team," the Freiburg striker said.

"If we defeat Argentina, we write a piece of World Cup history and many people in Switzerland proud of the team.

"I even think such success would see the world take notice, but we are not naive.

"It will take an absolutely top performance of each one of us. And I assure you, everyone will do everything we can to provide these and tearing for Switzerland."