Since returning to London, Lukaku has failed to live up to his £100million price tag after scoring just seven goals in 18 appearances.
However, those frustrations have now turned to anger following the 28-year-old's recent comments during an interview with Sky Italia.
The Chelsea number nine began by expressing his ongoing love for former club Inter saying: "I'm always thinking about Milano, Milano, Milano... Inter fans are the best in the world. I love the city and the best moment of my career was at Inter. I am in love with Italy - I have Inter in my heart."
If snubbing his current employers wasn't enough, Lukaku then spoke about his working relationship with manager Thomas Tuchel and hinted at a possible rift between the pair.
He said: "Tuchel and I are trying to find a tactical system where we can 'find' each other - a way to help the team because the situation is a bit complicated. He made his choice. I keep working, at a certain point I'll speak with Tuchel and we will see the situation."
To add more fuel to the fire, Lukaku didn't include his current club in a list of three which he believes are at the 'top level' - that's despite the fact Chelsea are the current Champions League title holders.
He said: "There are three teams at top level. Barcelona, Real, Bayern. All the players dream of them, that's the truth. I thought I was going to one of those clubs after Inter. This didn't happen and I said there is only one club where I can imagine myself, it's Chelsea.
"Last summer I didn't think about going to Chelsea until they really came with an offer. Simone Inzaghi behaved very well with me".
We're yet to discover the true motives behind Lukaku's interview but it's fair to say that the relationship between the striker and the club is at an all-time low.
However, even in the worst of times, there is still one way that Lukaku can win back the respect and adulation of Chelsea fans. That, of course, is through scoring goals… lots and lots of goals!
Players having rifts with their own clubs is nothing new. Back in 2004, Steven Gerrard faced death threats after being linked with a record-breaking transfer to Chelsea. Despite this, the midfielder went on to win back the love of Liverpool's supporters through his performances on the field - and a couple of trophies.
With that in mind, Lukaku still has a shot at restoring his status at Stamford Bridge. However, the bookmakers are beginning to doubt whether he is capable of scoring enough goals to appease the Chelsea faithful.
The forward marked his return to the club by scoring four goals in his first four games. Since then, he has only scored three more times in 14 appearances.
The same goes for his chances in the PFA Player of the Year betting market. Lukaku started out in the upper echelon of contenders, but now finds himself all the way down at 50/1 - right beside fellow underachiever Jack Grealish.
Then of course you still have the Champions League. Chelsea take on Lille in late February as they continue the defence of their European crown.
Lukaku has only scored two goals in the competition this season, and his odds of ending the European campaign as top scorer have drifted to an eye-watering price of 200/1.
The Belgium international finds himself behind the likes of Leroy Sane, Gabriel Jesus and even Sebastian Haller.
The road to forgiveness is a long one but every great journey must start with a single step. That first step could be this weekend as Chelsea take on Liverpool at Stamford Bridge.
Lukaku is priced at 7/5 to get on the scoresheet and you just know that a winning goal against the Reds would go a long way in healing a particularly nasty wound.