The 19-year-old, a Brazil-born Spain under-19 international, only joined the Portuguese club last month on a five-year deal from Real Madrid but he has moved to the Reebok Stadium to gain experience.

He is reunited with former Real team-mate Marcos Alonso, who joined Bolton in July.

"He is a quick, exciting young player who can play up front and in wide positions," said Wanderers assistant manager Sandy Stewart.