Romelu Lukaku enjoyed an extremely fruitful start to life at Manchester United, but he has been struggling massively in recent weeks.

The Belgian scored seven times in United's opening seven Premier League games, but he has added just one goal to that tally in his last eight.

That goal drought is certainly not ideal for Jose Mourinho, who will be looking for Lukaku to find his best form going into the Manchester derby later on Sunday.

But despite his recent struggles, Owen Hargreaves thinks that the 24-year-old could prove to be the most important player in Sunday's clash against their bitter rivals.

"United will need to get out of defence through Lukaku," the former United man said.

"Everyone said before he came to the club that his hold-up play was not good enough for a top, top player but in the past few weeks it has been much better.

"United need that so they can get players up the pitch. He could be the most important player in the game."

A PREMIER LEAGUE CLUB COULD HAVE SIGNED LUKAKU FOR A LOWLY FEE

Despite his struggles in recent weeks, Lukaku is still one of the best strikers in world football and his goal-scoring stats in recent years go along way in proving that.

Since the 2012/2013 season, the Belgian has been consistently deadly in front of goal: scoring 68 times in 141 appearances across five seasons.

That ability to find the back of the net on a regular basis eventually led to Man United shelling out £75 million for his services this summer.

But it has now been revealed that West Ham had the opportunity to sign Lukaku for £10 million when Sam Allardyce was boss.

However, Allardyce did not want to sign him on a permanent basis, and would only take him on loan.

West Ham's chairman David Sullivan told the Guardian: "I asked Sam if he fancied Lukaku.

"Sam said he’d take him on loan but he wouldn’t buy him for that (£10million). Again I’ve supported the manager."

Ouch.

Considering how West Ham have struggled to obtain a lethal goalscorer in recent years, they massively missed out here.

Acquiring a player of Lukaku's calibre for just £10 million could have gone down as one of the biggest bargains in Premier League history.