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Belgium are waiting anxiously on the fitness of their talismanic captain and centre-back Vincent Kompany, who is struggling with a niggling groin injury.
However, Wilmots said even without Kompany the 'Red Devils' should go through to their first World Cup quarter-final since 1986 and if they slipped up he would consider it a "failure".
The 45-year-old former international striker - who is Belgium's all-time scorer at the finals with five in the three World Cups he played at - also batted away criticism of the unconvincing manner in which his side won their three group games.
"I let people make their complaints, we just advance. We are not going to bang our heads against the wall," he said.
"When I see the team giving everything, I have no regrets. We have a young team, unbeaten for a long time in competitive matches."
Klinsmann - who is bidding to guide the United States to their second ever appearance in the last eight emulating the 2002 side - is also brimming with confidence and has told his players to push their flights back to after the July 13 final.
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