The forward, 31, scored 15 goals in 44 games in his second spell at Stamford Bridge but was ridiculed by the media and frozen out by the club who he claims tried to portray him as something he was not. Speaking to Italian paper Corriere dello Sport he revealed he was not the only squad member who was mistreated.
“I wasn’t alone at Chelsea. Aubameyang and Ziyech were also out of the project.
“They made us change in the youth locker room. It’s business, the club tells you it doesn’t want you anymore and often also where you’ll end up.
“But if you want to leave, even for serious reasons, you don’t have the option. They drag it out until the last moment, they wear you down.
“Clubs have relationships with the media, and it doesn’t take much to put a player in a difficult position or create the wrong image.
“Believe me, I’ve seen things I never thought I would. One day, I’d like to explain all of this to younger players, who is really working for them and who is working against them.'
The 31-year-old went on to reveal that he feels supporters always had the wrong impression of him in English football, where he would often be called overweight and lazy.
"In England they had the wrong idea," he continued. "For them I was lazy, but I never reacted to the attacks. I am someone who does his job and then goes home.
"In Italy, the opinion has been reversed, here I am a worker. Now (at Napoli) I am better than when I was at Inter. There I was 101kg, here 99kg."
During Lukaku's time at Chelsea, Roma and United, he played under legendary manager Jose Mourinho and reports claimed that the pair didn't see eye-to-eye, particularly as Mourinho sold Lukaku when at Chelsea.
“Nothing happened between me and him,' he explained. “Jose is a winner, I had him twice.
“I will never speak badly of him, at Roma he didn't have a top team, but he went all the way.”