New Delhi, Sept. 15 -- Fifteen-year-old academy star JJ Gabriel has asked Manchester United to cancel his registration with immediate effect, a shock request that has pulled him out of Wednesday's Carabao Cup tie with Brighton and left Old Trafford scrambling to keep one of English football's most talked-about teenagers.

Gabriel, who turns 16 on October 6, was lined up to make his competitive first-team bow at Old Trafford. Instead, he has submitted a formal notice seeking to leave, after missing training with Michael Carrick's squad late last week amid strain between his family and the club.

What is clear is the timing. Only last week, JJ Gabriel scored a hat-trick on his UEFA Youth League debut against Sabah, playing against boys two ...