"He's always changing things," the Jamaican sprinter told CNN ahead of the launch of his new film, I Am Bolt.
"Stick to one team! Stick to the same 11!"
After winning their opening three league games, United have picked up just 11 points from 10 games, leaving Mourinho's side struggling to qualify for next season's Champions League.
On Sunday, Mourinho was sent to the stands by referee Jonathan Moss after kicking a drinks bottle in frustration during the 1-1 home draw with West Ham.
The sole ever-present in United's English Premier League campaign has been goalkeeper David de Gea as Mourinho has juggled the demands of also playing in the Europa League and the League Cup.
Last season's breakout star Marcus Rashford has played in positions as disparate as center-forward, left-wing and -- controversially -- right full-back.
Meanwhile, despite 11 league goals and 15 assists for Borussia Dortmund last season, $44 million signing Henrikh Mkhitaryan has played just 133 minutes of Premier League football, prompting a #FreeMkhitaryan social media campaign.
United spent just shy of $200m on new arrivals in the summer, but it's already being speculated that the key to success could lie with Michael Carrick -- one of the club's longest-serving players.
The Red Devils are yet to suffer defeat with Carrick on the field this season and, though the 35-year-old was unavailable for selection in Sunday's draw against West Ham, Mourinho has only deemed it fit to play him in three Premier League games.
Bolt's belief that he could play for United
may be no more than a pipe dream, but when it comes to team selection, the world's fastest man might just have a point.