Fifteen-year-old former Barcelona prodigy Takefusa Kubo will be cleared to play for FC Tokyo's top-flight team, which could make him the youngest ever to appear in the J. League's first division, a club source said.

Kubo is currently 15 years, 3 months old. Former Japan forward Takayuki Morimoto made his top-flight debut at a league record of 15 years, 10 months and 6 days in 2004.

Kubo is expected to play for Tokyo's under-23s in J3 for the time being, the source said, but an appearance in J1 this season would make him the J1's youngest player ever.

Tokyo is stuck in mid-table anonymity again this year in ninth place, in neither championship contention nor danger of relegation.

Kubo caught the attention of Barcelona in 2011, when he was just in the fourth grade. But the Catalan club was later found to have violated FIFA's international transfer policy for under-18 youths, making Kubo ineligible to play for the Spanish giants.

He returned to Japan last year in search of playing time, signing with Tokyo's youth team. He is currently in India traveling with the national team for the Asian Under-16 Championship.