Lukaku, sold in 2014 to Everton after failing to score a single goal in Chelsea blue, will stand in front of the Shed End as the most expensive striker in British football
history, with 16 goals for club and country already this season and, most importantly, having finally persuaded Mourinho he belongs in the elite group of first-choice heroes he once found it so impossible to break into.
Quite what Chelsea fans will make of that remains to be seen; but given Lukaku had a choice to return ‘home’ last summer, but instead chose a move to Old Trafford, it’s fair to say the odds are on a rather uncomfortable reception.
In fact, an analysis of Lukaku’s career at Chelsea reeks more of missed opportunities, ‘could have beens’ and perhaps a lack of patience and understanding on both sides, rather than failure; and there may even be a feeling that had everything been done right, the striker should be turning out at Stamford Bridge on Sunday wearing blue and not red.
When he first arrived in west London, the connection Lukaku felt with the club was obvious and endearing. He spoke gushingly about his admiration for Didier Drogba, a player whom he idolised and whose game he attempted to replicate.
Seeing the pair together was akin to watching an older brother nurse his talented sibling through school, so obvious was Lukaku’s admiration for his teammate.
What an opportunity that was for the teenager to learn from the greatest player in Chelsea’s history - and yet they never played a single minute together in the same team.
The nearest they came to it was when Lukaku was given a rare start, against Blackburn in May 2012, and Drogba eventually replaced him from the bench.
Part of the problem was an injury-ravaged season for Drogba but Mourinho also has a history of relying heavily on experience and his ‘untouchables’ - which makes it tough for younger players to become first team regulars.
How ironic, then, that having been a victim of that philosophy at Chelsea, Lukaku returns to his former home having just been described in exactly those terms, as ‘untouchable’ by the Special One at Old Trafford.
The striker made just one Premier League start during his time in west London and didn’t score a single goal in any competition before eventually being sold to Goodison, which seems stranger when you consider his talent was never in doubt.
He proved it on loan at West Brom and Everton and even then his commitment to his ‘home’ club seemed unstinting. There seemed to be an affinity which hinted at a long-term relationship.
Of course almost every player these days claims to have been a ‘fan’ as a boy when he signs for a big club, but Lukaku’s rhetoric was convincing. First of all there was his undoubted admiration for Drogba, and additionally there was video evidence, a Dutch documentary of his time at a school in Brussels when a youth teamer at Anderlecht.
The cameras followed the teenager and his classmates on a field trip to Stamford Bridge where Lukaku said: “What a stadium. If one day in my life I will cry, it will be the day I play here. I love Chelsea.”
When you take all that into account, how on earth did Chelsea get it so wrong? In essence, those in power at Stamford Bridge - including Mourinho - believed Diego Costa was a better bet for future success than the player already on their books.
But there’s no doubt that with hindsight Lukaku would have been a better choice for the longer term. Just as strong, just as powerful, an excellent finisher and, year by year, growing in character. Oh, and no red cards in his career so far (in fact only 18 yellow cards).
Perhaps that’s Mourinho’s biggest weakness – because he rarely stays at a club for long before relationships break down, he is always in a hurry for success. No time to wait for a Lukaku or a De Bruyne (another player sold too soon), he needs those trophies now.
By all accounts, once they realised their mistake, Chelsea were first in the queue to bring Lukaku back from Everton - but his decision to choose United makes his return on Sunday even more emotional.
There is a caveat, however. Having scored 16 times already this season, Lukaku’s star should be on the rise; but after six games without a goal since that fast start, critics are lurking, ready to suggest he may not have the character or inner confidence to cope with the pressures of being United’s lone striker.
Even Mourinho, it seems, wanted to save him from the possibility of missing a penalty against Benfica in midweek, ordering Daley Blind to take it instead.
There are question marks, too, over what happens when the giant character of Zlatan Ibrahimovic returns to fitness. There is only room for one central striker in Mourinho’s team structure and so Lukaku will have to find that inner confidence quickly.
Barney Chilton, editor of United fanzine Red News, has confidence the player will be a success in the long term.
“He’s done very well so far,” he said. “People like to suggest the negatives, his touch for instance, but he’s a young, improving, switched-on striker. He will need to improve, but that’s what happens at United if you get it right.
“He’s tucking away chances - and if he can help create his own, and score the harder chances he could be crucial this season. Plus we also need to get more crosses in, because he’s very good in the air. A few former United
players expected him to do very well - they could see his development and he will only get better.”
As he heads back to London that verdict will be put to the test, especially when you consider Chelsea are hurting on the back of a 3-0 defeat in Rome and can draw on last year’s 4-0 win over United, the match in which Mourinho was taunted on his return to the Bridge.
It means there will no shortage of emotion or motivation on the pitch or in the stands - with Juan Mata and Nemanja Matic also playing against their former employers.
“There is pressure around the game of course but not just for Romelu, myself and Nemanja,” said Mata, another Chelsea player sold too soon, having been named Player of the Year two seasons in a row in west London.
“We remember the game last year but it’s not about revenge for us. It’s a totally different game. What happened last season happened last season and we have to think in the present. We have new players and I think Lukaku is having an amazing season.”
By tomorrow evening we’ll know how the Belgian coped; but whether he scores a hat-trick or is temporarily tamed by Gary Cahill it shouldn’t alter the fact that he has the ability to be United’s main striker for many years to come – and Chelsea should think very carefully about why they didn’t see it.