Brazilian veteran midfielder Gilberto Silva has warned the five-time world champions that they need to be ready for a Chilean ambush as their South Africa 2010 campaign enters the knockout stage.

Brazil were able to ease off against Portugal in their final group game having already won their opening two matches but the Panathinaikos star acknowledges that the nature of the tournament changes now.

"We have to redouble the attention we have been paying them," Gilberto said in an interview at Randpark Golf Club on the outskirts of Johannesburg.

The former Arsenal star echoed comments by teammate Robinho that previous good results against the Chile - Brazil have won their past five meetings - count for nothing now.

"It is a totally different game. We have a fine record against Chile but now it's decision time. We have had a good look at them - we saw them take on Spain (Spain won 2-1) and they gave a good account of themselves," he said. So we have to redouble the attention we have paid them."

They play without fear and have a good turn of speed. We have to watch out for them on the counter-attack as they know how to play.

Gilberto Silva, Brazil midfielder

Brazil had assumed all along that they would face Chile on the basis that they were expected to win their group and that Spain would take Group H, leaving their South bAmerican neighbours as runners-up.

"What we saw of them was that that they play without fear and have a good turn of speed. We have to watch out for them on the counter-attack as they know how to play and won't just stay back," said Gilberto.

He added that Brazil will be looking to improve as "we are conscious we didn't turn in a great showing" against Portugal, a dull 0-0 draw played out in the absence of the suspended Kaka and Robinho who was rested.

"We know we shan't be able to make so many mistakes - the Chileans can be dangerous. We will respect them."