The Jamaican, an all-time athletics legend after winning eight Olympic golds, retired after damaging his hamstring in his last ever race at the World Championships in London last year.
After recovering from that injury, the 31-year-old has reiterated his desire to switch sports, claiming he has held talks with the club's legendary former manager Alex Ferguson over a possible United deal, while his long mooted Dortmund trial is still on the cards.
"The injury is now fine and I'm back fully fit," Bolt, the 100 metres world-record holder, told the Express.
"In March we're going to do trials with Dortmund and that will determine what I do with that career, which way it goes. If they say I'm good, and that I need a bit of training, I'll do it.
"It makes me nervous. I don't get nervous but this is different, this is football now. It'll take time to adjust but once I play a few times I'll get used to it. It was the same when I started track and field.
"I was nervous for a while until I started getting used to the crowd, people and everyone around and it falls into place.
"One of my biggest dreams is to sign for Manchester United. If Dortmund say I'm good enough, I'll crack on and train hard. I've spoken to Alex Ferguson and I told him he needs to put in a good word. He told me if I get fit and ready, he will see what he can do."
Bolt, who won 11 World Championship gold medals in a glittering sprinting career, indicated he has sought advice from Paul Pogba over a potential football career.
"I do think I have a chance," Bolt added. "I watch a lot of football, I understand it, I play it. With training, I could be good.
"Me and Pogba talk a lot. I watch and ask him a lot of questions. I want to play but it has to be in the top league. I'm not content to be average.
"It's going to be hard because my career has been so great but if I could win a Champions League or something, it'll be close to anything I achieved in athletics.
"But I have to be more than average. It has to be in the top league because we have a lot of teams that have offered us deals, just random clubs. I want to be the best.
"I personally want to play on the wing but I know, listening to everybody and talking to footballers, that I will be put up top.
"I strive to be the best and if I get a chance to play for a team like Manchester United it will be a massive deal. I don't miss the sprint training. I miss the competition, and getting out on the track in front of the crowd, but not the training.
"I will definitely want to get up and go train and be excited just to play at Old Trafford."