The 17 year old defender was watched in reserve matches against Rangers and Hibs by Martin Ferguson, United’s chief scout, before Ferguson decided to approach the club asking if United could have a closer look at him.
Donaldson travelled to Manchester on Sunday accompanied by Livingston’s director of football John Collins, and will spend the week on trial.
Livingston have vowed not to stand in the youngster’s way if a move presents itself with chief executive Ged Nixon saying:
“Coll was watched by Man United in a couple of reserve games and Martin Ferguson wondered if they could have a look at him.
“They’re looking after him and he’ll train with them before they decide what they want to do.
“It’s a fantastic opportunity for the boy. No matter what happens in the end, it will let him see what’s out there and he’ll train in fantastic surroundings at Carrington.”