The Belgian striker remains a force of nature on the international stage, having scored five times for his country in just four internationals already this season.

That recalls the start he made to last season when, by this corresponding stage, he had scored five times in three Belgium games while also scoring 11 goals in 13 appearances for his club.

But Lukaku’s output for United has dropped off alarmingly this season, with just four goals in his opening dozen games for Jose Mourinho’s side.

And, while United have turned in strong second-half performances in last weekend’s draw at Chelsea and the previous come-from-behind victory over Newcastle, there remains the question of why their first-half showings have been so pedestrian.

“In the first half we started slowly — no initiative on the ball, no movement,” said Lukaku. “In the second half, everything that we said we wanted to do in the first half we did. That’s why we came back and got great results. Now the key is to start games like we do in the second half.

We have a plan every time we go against a team but I don’t know how to explain it. It’s just something we need to get out of. Offensively we are set up really well but then it’s on the ball where we need to make a difference.

The striker is similarly struggling to analyse why his own form has dipped from 12 months ago and, indeed, one has to delve back to 2014, when the then 21-year-old had only scored three times by mid-October for Everton, to find the last time he made such a slow goalscoring start to a campaign.

“I don’t know,” said Lukaku. “With Belgium I’ve been playing for 10 years, since I was 16. Players know me much more.

“Here I still think my teamwork between myself and my teammates can improve and be much better. It’s something that we’re working. The players need to know me and know my movement. When that starts clicking I think the results I have with Belgium will also come here.”