The former Middlesbrough striker who played a full season in the second division of English football has been snapped up by the Catalan giants in an €18m deal from Leganes.
After the injury to Ousmane Dembele ruled him out for six months, Barcelona have brought in Martin Braithwaite as a replacement from Leganes for €18m.
La Liga rules stipulate that any club whose player is ruled out of action for more than five months could sign a replacement outside the transfer window.
The rules further state that the replacement might either be a free agent or already playing in Spain, and that they cannot take part in any UEFA competition.
Braithwaite spent the whole of last season on loan at Leganes before making his transfer permanent by signing a four-year deal in July. He scored eight goals in 27 games for Leganes before putting pen to paper with the Catalan side earlier today.