Manchester United have let an unprofessional Romelu Lukaku leave because Ole Gunnar Solskjaer is trying to instil a "new culture" at Old Trafford, Gary Neville has told ESPN FC.

Lukaku has joined Inter Milan in a £72 million deal at the end of a week that saw the striker reprimanded for publishing confidential training data on Twitter and earn a fine from United for missing training on Wednesday.

"My view on Romelu Lukaku is that if Manchester United are trying to set a new tone and culture through the club, which Ole is trying to do, any lack of professionalism has got to be stamped upon," said Neville.

"He didn't want to be here anyway."

Lukaku scored 42 goals in 96 games for United following a £75m move from Everton in 2017.

He scored 27 goals in his first season but his form dipped last year and he admitted in December he had been forced to "lose muscle" after bulking up for the World Cup.

"I think he is a really good player -- he'll score a lot of goals and do well at Inter Milan," said Neville, who was speaking at an event to mark TalkTalk's new five-year partnership with Salford City FC.

"But the idea of a player being overweight for me is unforgivable. You can play badly, miss shots on goal, hit a bad cross or give goals away as they're mistakes in football but you can't be overweight.

"We were never overweight, not fit or not prepared. How can you be overweight!?

"There's no excuse. Romelu Lukaku has admitted himself that he was overweight so he has removed all doubt."