He might not be everyone’s cup of tea, but Jose Mourinho clearly loves working with Romelu Lukaku. The Portuguese coach has brought the Belgian striker to AS Roma on a season-long loan deal. That’s now three clubs the pair have worked together.

Mourinho first coached Lukaku at Chelsea after returning to Stamford Bridge for his second stint at manager in 2013. However, their relationship didn’t get off to the best of starts after Lukaku, aged just 20 at the time, missed the decisive penalty in the 2013 UEFA Super Cup against Bayern Munich and then forced through a loan move to Everton, fearing he wasn’t able at that point to compete with Fernando Torres, Demba Ba and Samuel Eto’o.

Months later, Mourinho hit back at Lukaku when asked for a response to comments the forward made claiming the then-Chelsea boss hadn’t been in touch. Mourinho said: “Romelu is a young boy who likes to speak. The only thing he didn’t say is why he went to Everton on loan. That’s the only thing he never says.”

Lukaku was a big success at Everton, scoring 16 goals in 33 games, and it came as a shock when Chelsea allowed the talented young forward to join the Toffees permanently in the summer of 2014. Everton’s then-manager Roberto Martinez described the club-record £28 million transfer as a “significant day in the history of this football club.”

While the relationship between Lukaku and Mourinho felt frosty at best at the time, there was still deep mutual respect for each other. We know this because the pair reunited at Manchester United in July 2017. After scoring an impressive 87 goals in 166 games for Everton, Lukaku was brought to Old Trafford in a deal worth £75 million.

"When Manchester United and Jose Mourinho come knocking at the door, it is an opportunity of a lifetime and one that I could not turn down,” Lukaku told reporters, per BBC Sport. "I cannot wait to run out at Old Trafford in front of 75,000 fans."

Mourinho added: "Romelu is a natural fit for Manchester United. He is a big personality and a big player. It is only natural that he wants to develop his career at the biggest club. He will be a great addition to the group. I am really looking forward to working with him again."

Why did it go wrong for Lukaku at Man United?

It felt like a great move for both Lukaku and Man Utd, although some had reservations, including former Red Devils’ captain Gary Neville, who tweeted at the time: “He's incredibly talented and I've seen him destroy defences but personally I've never been his biggest fan. However, he will score goals.”

Lukaku did indeed score goals - 27 in 51 games during his first campaign at the Theatre of Dreams. But that goal every other game record doesn’t tell the full story of Lukaku’s first year with the Premier League giants.

Leading the line for Man Utd is one of the more pressurised positions in world football and there were many games where Lukaku was derided by fans and pundits alike for missing too many chances. His first touch also became a huge talking point. Almost every time he’d miscontrol the ball, clips would spread like wildfire on social media. A vicious circle began to form.

Lukaku’s physique also came under scrutiny, with some people suggesting that his work inside the gym had caused him to become too muscular. The lean, quick forward that terrified defences at Everton had been replaced with a heavy, sluggish striker who appeared to be losing more and more confidence with each passing week.

Mourinho was sacked midway through Lukaku’s second season at Man Utd and replaced by interim coach Ole Gunnar Solskjaer. While he had some decent moments under the Norwegian coach - including an excellent performance away at Paris Saint-Germain in the Champions League knockout stages - Lukaku ended the 2018-19 campaign with a disappointing 15 goals in 45 matches.

When Lukaku leaked Man Utd players' speed stats

One week before he left Man Utd for Inter Milan in a deal worth a reported £73 million, Lukaku angered his manager and teammates by leaking data from training in an attempt to end negative comments about his speed. He controversially uploaded a short video showing every United players’ maximum speed following a drill in training, with the caption ‘lack of pace’ next to a laughing emoji. Check out the stats below:

As you can see, Lukaku registered the second-highest top speed from the session, ahead of Marcus Rashford and Daniel James, who now plies his trade with Leeds United. Diogo Dalot finished in first place with a speed of 36.43km/h, with Lukaku just behind at 36.25km/h.

Surprisingly, Luke Shaw was the slowest player listed, clocking a slower time than Nemanja Matic, Juan Mata and Scott McTominay with a top speed of 31.03km/h. However, Shaw responded to Lukaku via Twitter saying that he was only asked to go at 70 per cent, adding: “Don't let me start speaking on you boy.” Meanwhile, Mata replied: “Thanks for finally showing the world that I'm quicker than Luke Shaw bro.”

The Daily Mail reported at the time that Lukaku was told by Man United to delete the tweet as it contained confidential details from the squad sprint session. The report added that a number of United players were unhappy with Lukaku’s tweet, and you can certainly understand why.

READ MORE: Inter helped Romelu Lukaku lose half a stone in 12 days after Manchester United missed problem

Lukaku's topsy-turvy career since leaving Man Utd

Since leaving Old Trafford under a cloud, Lukaku has had an extremely topsy-turvy few years. He bossed it during his two seasons at Inter, scoring 64 goals in 95 games, before completing a £97.5 million return to Chelsea in August 2021.

Lukaku was a bitter disappointment at Stamford Bridge, netting 15 goals in 44 appearances, and subsequently returned to Inter for the 2022-23 campaign. Unwilling to return to his parent club, Chelsea have now loaned Lukaku to Mourinho at Roma.

Will it be third time lucky for the pair? Now 30 years old, this latest loan move to the Stadio Olimpico is likely to be one of the most important of Lukaku’s career.

READ MORE: Jose Mourinho: The 10 best and 10 worst signings of his career