The Belgium international signed for the Blues for the second time in his career in August for a reported club-record fee of £97.5 million ($180.6 million).

Lukaku later said he spoke to Inter boss Simone Inzaghi to plead for the chance to go back to Chelsea, the club he first joined from Anderlecht in 2011, as he felt he had unfinished business in the Premier League.

Inter fans were angry with Lukaku's determination to leave just weeks after they had celebrated a first Serie A title in 10 years, with the striker having played a critical role in their success under Antonio Conte.

Lukaku was directly involved in 35 goals (24 scored, 11 assisted) in 36 league games, the most of anyone in Italy's top flight, and he was named Serie A's MVP for his performances.

He has not been as successful in his first season back in England, though, starting just eight times in the Premier League amid injury and COVID-19 problems.

Lukaku scored in the 3-1 win over Aston Villa and Thursday's (AEDT) 1-1 draw with Brighton and Hove Albion, his first league goals since September, but claimed he wanted clarity from head coach Thomas Tuchel about his role in the side.

Now, the former Manchester United forward says he is unhappy with matters at Chelsea, which has fallen eight points behind league leader Manchester City after two wins in six games, and has made a promise to return to Inter before he enters the twilight of his career.

He told Sky Sport Italia: "Physically, I'm fine, even better than before. After two years in Italy, in which I worked a lot at Inter with coaches and nutritionists, I'm physically doing OK.

"But I'm not happy with the situation. This is normal. I think the boss has chosen to play with another system. I just have to not give up and continue working and being professional.

"I'm not happy with the situation, but I'm a hard worker and I must not give up.

"I don't think everything that happened was supposed to happen like that. The way I left Inter, how I communicated with the fans, it bothers me because it might not be the right time now [to say it] but it wasn't the right time when I left, either.

"Now, I think it's right to talk because I have always said I have Inter in my heart. I'll go back to play there, I really hope so. I love Italy; this is the right time to talk and let people know what happened without speaking badly about people, because I'm not like that.

"I want to say a big apology to the Inter fans because I think the way I left should have been different. I should have talked to you first because the things you've done for me, for my family, my mother, my son, are things that will stay with me for life.

"I really hope, from the bottom of my heart, to return to Inter. Not at the end of my career, but while I'm still at a good level to hope to win more."