Marc Jurado, Alvaro Fernandez and Isak Hansen-Aaroen, have all been fully signed by Manchester United, according to MEN.
As they remain in quarantine for now, the three teenagers have confirmed their moves on Instagram and Spaniards Jurado and Fernandez have posed in training kits.
International clearance for Norwegian Hansen-Aaroen, who turned 16 last week, is still being awaited by United.
By following Fifa rules, players require clearance from both relevant football associations.
Fernandez have been completely cleared but still awaiting it from the Football Association for Jurado
Jurado, 16, and Fernandez, 17, have already started intensive English lessons and have been introduced to their new coaches via Zoom calls.