Real Madrid are closing in on signing JJ Gabriel, though Manchester United will consider legal action if the club believe any rules have been broken.

Madrid have offered the 16-year-old forward a multi-year contract and, subject to final talks, hope to bring him to the club in January. Gabriel is registered with United’s academy until the end of the season and it is understood the club have yet to be contacted by the player’s camp or Madrid regarding the proposed move.

Madrid intend to sign Gabriel via a Fifa loophole that allows clubs in the European Union to tie down young players to professional contracts if they have an EU passport, which Gabriel is eligible to acquire through both his parents.

Fifa would have to sign this off and United are on alert regarding any potential breach of regulations. A compensation fee would be due to United if Gabriel joined Madrid or any other team. Madrid have been approached for comment.

Gabriel walked out on United in September and is believed to be training in Spain. A move to Madrid offers the prospect of progression to senior football via their B team, Castilla, who play in the regionalised Spanish third tier.

Gabriel made his United debut in a pre-season friendly against Atlético Madrid in Stockholm on August at the age of 15 and had been training with the first team. If he had not informed United of his wish to depart, he would have been in Michael Carrick’s squad for the 3-2 Carabao Cup defeat by Brighton on 16 September. Had Gabriel featured, he would have become the youngest player in the club’s history.

Gabriel last season became the youngest winner of United’s academy player of the year award and was the Premier League’s Under-18 player of the season.