The Frenchman has criticized Fernandes after United decided to dismiss their manager Erik ten Hag on Monday.
Petit, who played for Arsenal and Chelsea before becoming a football pundit, feels players like Fernandes were at fault for Ten Hag’s dismissal.
Fernandes has attracted plenty of criticism since he became United captain, with many people slamming him over his body language and lack of leadership.
‘The body language of the [Man United] players has been awful,’ Petit told Jeffbet.
‘Bruno Fernandes annoys me a lot, I really just want to tell him to shut up. He was terrible [at] West Ham and he was a terrible captain, he’s not captain material. There needs to be a reaction from these players.’
Speaking more generally about Ten Hag’s sacking, Petit added: ‘It was about time. I’m sorry to say that and I pity him because lots of the players at the club are far from their best.
‘When I watched the game against West Ham, even I was frustrated for the Manchester United fans.
‘They concede goals easily, they are a mess. Ten Hag had no support from the fans, the club or the players [even though] he is responsible for a lot of the issues.
‘Players must share this responsibility, though, they are the reason he’s been sacked.
‘[However], Ten Hag is responsible for bringing in average Dutch players from the Eredivisie.
‘Ten Hag showed no passion either, he always seemed bored in press conferences. The only consistent thing at Manchester United now is their average performance, which has been happening for years now.
‘Even with a change of manager, nothing will change. If I’m a manager linked to Manchester United, a big club with lots of money, I’d look at that club and ask what is the project? What are the ambitions? I don’t see anything worth joining them for.’