Alexis Sanchez worried about refereeing standards

Chile winger Alexis Sanchez has indicated that he wants to see a strong refereeing performance from Howard Webb ahead of his team's last-16 clash with Brazil on Saturday.

La Roja felt that several decisions went against them in their final group game with the Netherlands on Monday, and ahead of their fixture with the hosts in Belo Horizonte, Sanchez has admitted that he is concerned about the performance of the English official.

The 25-year-old is quoted by ESPN as saying: "I am very happy to be playing against the hosts, against the best defence in the world, a team with impressive quality. However, what most worries me is the refereeing. We will see what happens."

Chile qualified for the second round with victories over Australia and Spain.