Argentina boss Alejandro Sabella has insisted that he wants his side to raise the level of their performance in their World Cup quarter-final clash with Belgium.

La Celeste struggled in their second-round game against Switzerland, until a moment of magic from Lionel Messi unlocked the Swiss defence allowing Angel di Maria to hit the winner in extra time.

"We have reasons for things, extenuating factors. But we have not reached the level we wanted to reach," Sabella told reporters.

"We're looking for an improvement. But we've seen that this is a very difficult tournament with very even matches."

Sabella's side face off against Belgium in Brasilia later today.