Romelu Lukaku latest: Is the Everton forward right to go to Manchester United over Chelsea? – Transfer assessed
talkSPORT has taken a look at the two clubs seemingly in the race for Lukaku, in a bid to work out which is the best option...
How he will fit in
With both clubs on the lookout for a new first-choice forward, it looks like he would start in both teams.
Manchester United released Zlatan Ibrahimovic in the summer, a man whose 28 goals and 10 assists were key to the club's sixth-placed finish and triumphs in the EFL Cup and Europa League.
In comparison, Lukaku scored 26 and set up seven in an Everton side with much less creativity. In Mourinho's preferred 4-2-3-1 formation, Lukaku could be the focal point of the team with the likes of Henrikh Mkhitaryan, Paul Pogba and Juan Mata supplying.
He has often been criticised for not scoring against the big teams, but with these world-class players providing good service to suit Lukaku's range of skills - hold up play, instinctive finishing in the box, his left foot - he should find the net on a consistent basis.
Manchester United often struggled to find the breakthrough at home last term and they failed to turn draws into wins. Not only could Lukaku help with goals, his movement and physicality against opposition defences could open up space for United's attackers to create further chances.
Chelsea, meanwhile, are close to sanctioning Diego Costa's return to Atletico Madrid and will be in the market for a top-quality striker as they return to the Champions League, while looking to secure back-to-back Premier League titles.
Costa and Lukaku are quite similar in the sense they are physical strikers who are clinical in the box while possessing a surprise turn of pace.
Chelsea are expected to receive around £22million from Atletico, while they will have to fork out around four or five times as much to bring back Lukaku, a man they sold for just short of £30million in 2014.
Costa racked up 22 goals and eight assists for Antonio Conte's side and when Costa was unavailable or out of form, they missed him in the final third. Chelsea's season-changing 3-4-3 formation features a fluid attack, but you would imagine it to be more rigid in order to get the best out of Lukaku, allowing Eden Hazard to keep his free role but also to keep their width, allowing Lukaku to attack free spaces through the middle.
Should they lose Costa and miss out on Lukaku, Andrea Belotti could be their next option, but he will not prove any cheaper as he has an £86million release clause in his Torino contract.
Both sides' alternative to Lukaku is Alvaro Morata (Manchester United and Chelsea) and Belotti (Chelsea) and Lukaku has something the two do not - Premier League experience, he is proven and well suited to England's top flight.
Managers
Jose Mourinho is a man Lukaku knows from their time at Chelsea - the Portuguese boss sent him out on loan before approving his sale in 2014. He was often critical of Lukaku's attitude as the Belgian wanted to be first choice at Stamford Bridge, but Lukaku has clearly proved to Mourinho he is of the quality to lead United's line next term.
When Lukaku left Chelsea for good, Mourinho was one of the first to wish him luck via text and that move probably helped in making sure the pair parted on good terms.
That move would complete Mourinho's spine of the Manchester United team - David De Gea, the newly added Victor Lindelof in defence, Ander Herrera and Paul Pogba in midfield and Lukaku leading the line, certainly a good starting point.
A return to London would see him link up with Antonio Conte for the first time in his career, and you can certainly see the Italian boss getting the best out of him.
Andre Villas-Boas, Roberto Di Matteo, Steve Clarke, Roberto Martinez, briefly Jose Mourinho and Ronald Koeman - they are the managers Lukaku has worked with since arriving in England in 2011 and a manager of Conte's calibre is an attractive proposition.
Conte's tactical nous could improve Lukaku's game considerably, especially playing the 3-4-3 formation, as mentioned previously. Lukaku would learn when to drop in and out of positions more often, taking in different aspects of the game.
You feel under Mourinho he would keep doing what he did last season - possibly adjusting quicker - while Conte would help his game improve further but it would possibly take more time.
Environment
Signing for Manchester United means Lukaku can stay settled in the north west, probably not even having to move.
He would undoubtedly settle quickly due to his well-known friendship with Manchester United's current world-record signing in Paul Pogba.
Both are 24 years old and share the same agent in Mino Raiola. They are currently on holiday together in Los Angeles, something you would know by following either of the two on social media. This closeness could also help on the pitch, with an understanding that could see Pogba really come into his own as well as Lukaku.
Chelsea is a place all too familiar to Lukaku, so moving there would be nothing new, with the chance to return to England's capital.
From Stamford Bridge to the club's Cobham Training Centre, Lukaku will soon find his feet and there are members of the Chelsea team still present from his time there, including Belgium team-mate Eden Hazard.