The LaLiga champion confirmed it has signed the striker after triggering an €18million release clause in his contract.

Barca was granted special dispensation to sign Braithwaite outside of the transfer window after losing Luis Suarez and Ousmane Dembele to long-term injuries.

LaLiga struggler Leganes has been blocked from bringing in a replacement forward, however, much to the frustration of the club's general director Martin Ortega.

Ortega accused the league and the Royal Spanish Football Federation of causing Leganes "irreparable damage" and has asked for the rule to be amended.

Speaking at Braithwaite's introductory news conference, Bartomeu agreed the loophole needs to be looked at.

"We have paid the clause following the regulations, although we believe that it should be revised because it is not fair that Leganes cannot now sign anyone," he said.

Barcelona's decision to sign Braithwaite has raised eyebrows, but Bartomeu believes the former Middlesbrough forward can be a big asset for the club this season and beyond.

"After analysing different players, we chose Martin. We believe it will help us win the two remaining titles," he said. "I am very excited about the arrival of a new player and we hope he will help us in a league that we want to win and that is very open. He will give us strength.

"We had a long-term injured player like Dembele, in addition to Luis Suarez. The technical team has studied players and we hope Braithwaite can debut quickly.

"He has signed for the next four and a half years and comes to help now and for the future."

Braithwaite could make his debut when Eibar visits Camp Nou this week, and Barca director Eric Abidal is happy with the new arrival.

"Martin is a Denmark international, with experience different from those players we have," said Abidal, who dodged questions regarding his recent row with Lionel Messi.

"He has character, strength, speed and great potential. I have had the opportunity to speak with coaches he has had. He will contribute a lot and be decisive. 

"Hopefully, we can compete with him at the highest level."