United have conceded 18 goals in 11 Premier League games so far under manager Ruben Amorim who has led his side to a resurgence in recent weeks after a dip in form.
Bolt, an avid United fan, sent a voice note to the Rio Ferdinand presents this week and ripped into his side, who he believes have no idea how to defend.
"I just watched the United game, one of our biggest problems is when we invite pressure onto ourselves. They're always running back, all we do is invite pressure. Please (Rio), I'm begging you man. Get to the team and say something.
“You are one of the greatest defenders Man United ever had, please bro, it's stressing me out. I know you have nothing to do with this but tell the guys to pass the ball quicker. Oh my God, bro.
“They don't know how to defend one-on-one. Shaw is the only one who seems like he understand. All they know is system, line up and play well. 'They don't know how to step up, push the defender and then go back into your line. I push up (as a defender) and the midfield slots in. Please, Rio, get to somebody."
Despite securing impressive victories over Chelsea, Liverpool and Brighton and Hove Albion this season, The Red Devils have kept just one clean sheet in 12 games this season, conceding 20 goals.
Amorim’s side do appear to have turned a corner in recent weeks, however, winning three and drawing two of their last five outings. But, if they want to keep consistency up they must fix their leaky defence like Usain says and maybe introduce legends like Ferdinand into the training groud to improve aspects at the back.