The Netherlands prepare for a tough game

Holland boss Bert van Marwijk has warned his side must raise their game even further when they face Slovakia in their World Cup last-16 clash.

Van Marwijk's men reached the knockout stages with an impressive three wins from three group matches against Denmark, Japan and Cameroon.

Next up they face Slovakia in Durban on Monday, meeting a side who beat defending champions Italy 3-2 to clinch a place in the next round.

"I think everyone was impressed by Slovakia," said Van Marwijk, whose side laboured at times in their dead rubber with Cameroon before sneaking a 2-1 win.

"I said before the match that it wouldn't surprise me if Italy were beaten by Slovakia and that's exactly what happened.

"They are an opponent we must not underestimate. If we are just as concentrated as in our first two group matches and in moments against Cameroon then we can show ourselves at our best.

"We must be patient to score goals, we've got speed we can use, but we can't afford to play like we did for periods against Cameroon when we were so nonchalant."

Striker Robin van Persie agreed with his coach.

"Slovakia will be very tough," he said.

"I saw bits and pieces of their game and to beat Italy like that was unbelievable.

"We need to be really sharp when we play them."

The availability of winger Arjen Robben is still uncertain after he came off the bench against Cameroon to make his first appearance of the tournament following hamstring trouble.

Van Marwijk is expected to err on the side of caution and keep him on the bench again when Holland face Slovakia.