Cape Town - Inter Milan striker Romelu Lukaku has hit back at criticism from pundit Gary Neville, insisting that his professionalism should never be called into question.
Neville was scathing in his assessment of Lukaku in a Twitter post after the Belgian completed his big-money switch from Manchester United to Inter Milan earlier in the month, writing: "He is over 100kg! He's a Manchester United player! He will score goals and do well at Inter Milan but unprofessionalism is contagious."
And Lukaku, who scored 42 times in 96 appearances for United, has hit back at the 44-year-old.
In an interview with BBC Sport, Lukaku said: "He (Neville) can talk about my fitness but he should never say anything about my professionalism, that I don't work hard enough. That is something he cannot say.
"All the coaches I have had say the same thing about me. What did Ole Gunnar Solskjaer say when I was on the training ground?
"What did he say? That I always work hard and always do my best to try and improve myself. Same with Jose Mourinho and Roberto Martinez. Now Antonio Conte will say it.
"Last year was just a bad year. It happens in football. You just have to move on. I am not going to sit here and react in a negative way.
"We are grown men. He is a pundit. He gets paid to say this kind of stuff. I am paid to play football. I just want to do my best for Inter Milan. That is it."
Lukaku spent two seasons at United following his transfer from Everton in 2017.
The 26-year-old insisted he is grateful for his time at Old Trafford but rued the fact he did not win a trophy during his spell.
He added: "For me, the Manchester United experience is one I am grateful for, not a good one because we didn't win and I wanted to win with the club. But they gave me a chance.
"I got to play for one of the biggest clubs in the world, so I will always be respectful to them. At the end, I thought it was better for me to move on and try different things.
"I wish them well for the future. Now I am on my own path and I am very happy in Serie A."
Lukaku enjoyed a strong start to life in Italy, scoring on his debut as Inter beat Lecce 4-0 on Monday.