The sprint sensation, who won three gold medals at the Olympics, has made no secret of his love for United nor his desire to one day play for the club.
After asking Rio Ferdinand to set him up for a trial via Twitter, the Jamaican was a guest of the Reds before the recent win against Fulham and paraded his medals before the crowd at Old Trafford.
"He's been to Carrington a couple of times," Sir Alex told Inside United in his exclusive column. "And he did help Cristiano Ronaldo with his sprinting, like he said. He took him aside one day.
"He's a bit of a character and a big United fan. But it's interesting he says he'd like to play in a charity game. It could be brilliant and next year, when we play Real Madrid's Legends again, there could be opportunities to bring him up and see how he does.
"The people from these small islands, like Dwight Yorke from Trinidad & Tobago, they all play football and he probably played at school level or youth level or something like that. It'd be nice to get him up here, I think it'll be good."
Bolt's performance at the London Games certainly further endeared himself to the United manager as the boss had a vested interest in the 26-year-old leaving his rivals trailing in his wake.
"He was phenomenal," enthused Sir Alex. "I must thank him because that was my biggest bet.