Brooks, who owns Ole Futsal Academy in East London, has worked with nearly 1,000 young players and believes Gabriel is the most talented he's ever coached.
Gabriel has been training with Manchester United's first team since last year and has played for the U21 team.
Brooks stated, "I've coached many young players, but JJ is the most skilled I've ever seen. He could join a Premier League team and excel technically - there's no doubt about it."
Before joining Manchester United, Gabriel played for junior teams at Chelsea, Arsenal, and West Ham United.