United had spent most of the transfer window focused on signing Morata and had made progress, albeit slow, in negotiations with Real Madrid to the point whereby a £58million deal was in sight.
Mourinho had worked with Morata at Real Madrid and the forward was keen on moving to Old Trafford but once United got wind of Chelseas hesistancy over a deal for Lukaku they moved swiftly to take the Belgian to Old Trafford.
Chelsea, furious and desperate to save face, wrapped up a deal for Morata within a fortnight; setting-up an intriguing sliding doors narrative for the two forwards at their new clubs.
Lukakus familiarity with Premier League audiences dampened some of the excitement that normally comes with a £75m signing. United fans questioned Lukakus first touch, his work-rate and in particular his build-up play.
Fears over Lukakus suitability to United were borne out of supporters distrust of Mourinho. Old Trafford had grown accustomed to the likes of Robin van Persie, Dimitar Berbatov and Wayne Rooney.
For some, Lukakus arrival only reinforced their worst fears about Mourinho and that the club had departed entirely from the days of Sir Alex Ferguson. It raised the probability that the club would have to adapt to Mourinho, rather than him to them.
Lukakus every touch was being scrutinised but he allayed some of the early fears during a blistering start to the season where he scored 11 goals in his first ten matches for the club.
It was, by all accounts, an emphatic start but Morata also hit the ground running, scoring seven goals in his first eight games for Chelsea. While he wasnt as consistent a goal threat, Moratas play was slicker and, just as crucially, was proving an effective foil for Eden Hazard in a two-man attack.
United were level with Manchester City on 19 points at the end of September following Lukakus fast start but the Belgian was about to embark on a prolonged dry patch that would cost Mourinhos side a title challenge.
After scoring against Crystal Palace on September 30th in a 4-0 win, Lukaku would have to wait over six weeks and eight games for his next goal. The run emboldened Lukakus fiercest critics and Moratas bullet header in a 1-0 win against United at Stamford Bridge piled further pressure onto the Belgians shoulders.
Lukakus strike against Newcastle in mid-November ended a run of 463 minutes without a goal but at no point was Mourinho tempted to drop the 25-year-old. In fact, perhaps here more than at any other stage this season, Mourinho felt vindicated by his decision to opt for Lukaku over Morata.
Mourinho on Lukaku's poor form in front of goal
For me, the most important thing is team-work and hes second-to-none in terms of giving everything he has to the team
2nd December 2017
The Belgian was furious with his form in front of goal, displaying the type of anger and hurt that Mourinho wants to see from his players when theyre not performing. But while his confidence in front of goal was dimishing with every game, Lukaku was contributing elsewhere. In a 1-0 win against Tottenham, Lukaku provided a crucial assist for Anthony Martial in the dying minutes. Against Arsenal he broke at speed and played a key role in Jesse Lingards first of two goals at the Emirates in a 3-1 win.
Lukaku was still doing all the right things and Mourinho knew dropping the striker was futile. Paul Pogbas hamstring injury meant United had lost their talisman and most creative player. Dropping Lukaku would only further expose the fact that Mourinho had failed to create a cohesive attacking system that wasnt reliant on individuals after spending close to £300m at the club.
But this was about more than just performances. Since moving to Old Trafford Mourinho has sought experience, know-how and maturity. The signing of Zlatan Ibrahimovic helped some of Uniteds more fragile squad members and the arrival of loyalist Nemanja Matic has helped Mourinho spread his message around the dressing room. In Lukaku he has found an old head on young shoulders and he counts the striker now as one of his guaranteed starters.
When United were dumped out of the Champions League by Sevilla in the last-16, Mourinho blasted practically ever single member of his squad but spared Matic and Lukaku.
Mourinho questions mentality of Man Utd squad but exempts Lukaku & Matic
If you want to make a real top team, with a top mentality, you need to grow up and the best way is to have this kind of feeling. Players have to learn how to cope with that level of expectation and that level of pressure. They have to survive, and when they survive, they become stronger. I said we are not one of the top teams, not one of the favourites to win. I told you that with these words because I cannot tell you with different words while I am still in competition. I cannot be in a competition, go there and say we have no chance. I couldnt tell you You cannot expect me to say this and that player, they have to do better. I prefer to say that Matic and Lukaku are performing at a high level until the last match.
While Lukaku persevered, Morata struggled for consistency in Antonio Contes turbulent second term in west London.
By the turn of the year Morata had 13 goals to his name: certainly not the worst return for a young striker adapting to a new league. But seven of those came in his first eight games and Moratas added just three goals in all competitions in 2018.
Morata's drop in form
First 9 apperances: 7 goals
Next 39 apperances: 8 goals
The former Real Madrid man has been carrying a back injury and took injections over the new year to enable him to play through the pain. That has undoubtedly hampered his debut campaign with the Blues but Olivier Girouds arrival from Arsenal in January appears only to have muddled Moratas mind.
As Chelsea prepare to take on Manchester United in the FA Cup final Morata will be worried about his starting spot. The striker credits Conte with saving his career at Juventus but he finds himself under increasing threat from Giroud and Contes departure this summer raises serious question marks over his long-term future at Stamford Bridge. Juventus are known to be keen on re-signing the striker.
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Lukaku, meanwhile, faces a race to be fit for the Wembley showdown. Mourinho will give the Belgian every opportunity to prove his fitness before Saturday and will allow the striker to make the final decision on whether he can start – such is the level of trust between the two.
Its that level of maturity that Lukaku believes has led him to becoming one of Mourinhos sergeants on the field.
Romelu Lukaku on being Jose Mourinho's 'sergeant '
I think the manager in his mind thinks that Im like his sergeant on the pitch, and thats strange for a striker because its usually the midfielders. He has been really good but I think he knows I have that soldier mentality.I think the work rate I am delivering to the team is a lot and he knows he can come to me whenever. I will always put the team first ahead of myself and thats something I told him, I said the team is the most important thing
8th March 2018
Saturdays final is an opportunity for both clubs to end the season on a high note. The game is likely to be Contes last as Chelsea manager and a trophy would add gloss to a season of progress under Mourinho at Old Trafford.
Lukaku travelled with the rest of the United squad to London yesterday and will need to pass a fitness test to start at Wembley. Mourinho will be hoping he can upstage Morata one final time this season for the Red Devils to win the FA Cup for a record-equalling 13th time.