The Everton star is yet to find his form at this year’s competition, and has been taken off the field before the hour mark in both of Belgium’s opening two fixtures.
Yet his national coach feels the forward’s slow start to the tournament was to be expected from the young 21-year-old.
“He puts too much pressure on himself,” Wilmots, a former Belgian international himself, told FIFA.com.
“I messed up in my first two World Cups because I was obsessed with winning.
“I was expecting the younger players to handle the occasion less well, simply because they would be thinking about nothing else but the need to win.”
Yet Wilmots knows his front man can do better and feels he is still an important member of the Belgian set-up.
“I know Lukaku can do better and he knows that too,” said the 45-year-old manager. “He’s still very important for us.”
Belgium as a whole have been less-than-impressive in Brazil so far, grinding out victories over Algeria and Russia by one-goal margins, yet find themselves on top of Group H and secured of qualification for the Last 16.
“Maybe it hasn’t been very spectacular, but we’ve achieved something big with one of the youngest squads in the tournament,” said their coach.
“I’ve been pleased by the discipline, teamwork and patience of my players.”
Despite already through to the knockout stages of the tournament, Wilmots is looking to continue their winning form in the final group encounter against South Korea.
“We won’t have to do any maths or ask ourselves whether it’s better to defend or attack,” he said. “We’ll just go out and look for the win.”
Kick-off against South Korea in Sao Paolo is scheduled for 10pm South African time.