FIFA has rejected Barcelona's appeal against their transfer ban, meaning the Catalans cannot sign players in the next two windows
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Barcelona have reached a preliminary agreement with Sao Paulo to sign Brazilian defender Douglas.
The 24-year-old right-back will undergo a medical in Spain later this week before signing a five-year deal with the Primera Liga giants to become Barca's sixth reinforcement this summer.
Javier Mascherano has signed a new four-year contract with Barcelona.
The deal, which was agreed before this summer's World Cup, ties the Argentina international to the Nou Camp until June 30, 2018, with the option of a further year on top of that.
The versatile 30-year-old midfielder said: "I'm committed to this club until the final day of the contract. I hope I can live up to expectations of the club.
"I'm really happy to be in this great club and be part of a squad with such great players. Let's hope things go really well for us this season. We're looking forward to this season after some difficult times last campaign."
A Lionel Messi brace and a delightful finish from teenager Munir El Haddadi kicked off Luis Enrique's Barcelona reign with a 3-0 win over Elche in the Primera Division.
Messi got back to his marauding best and scored the opening goal before Javier Mascherano saw red in the closing stages of the first half.
With Barca down to 10 men Munir stole the limelight, latching on to a ball over the top from summer signing Ivan Rakitic before deftly flicking it into the top corner with the outside of his left boot.
Messi had the final say though, shrugging off four defenders and lashing home to remind everyone of his sensational talents just after the hour-mark.
Neymar has likely been ruled out of Barcelona's season-opening game against Elche after spraining his ankle.
The Brazilian forward has only just recovered from the cracked verterbra he suffered at the World Cup finals and was back in full training ahead of Sunday's Primera Division match at the Nou Camp.
Barcelona have announced they will appeal to the Court of Arbitration for Sport after FIFA on Wednesday upheld their transfer embargo until January 2016.
The world's football governing body turned down the Catalan club's appeal to overturn a two-window transfer ban, which was handed to them in April due to concerns over the "international transfer of minors".
Gerard Deulofeu admits he was surprised that Barcelona allowed him to go out on loan again after completing his switch to their Primera Division rivals Sevilla - but he is determined to make the most of his "key" year in Andalusia.
– Sevilla forward Gerard Deulofeu
I'm very happy to be here, (new Barcelona coach) Luis Enrique told me that I wouldn't be playing, and from the first moment I had my mind set on coming to Sevilla.
It's a very good club, I have high expectations and hopefully we can have a great year together.
I was surprised by the decision that the manager took, but I'm going to enjoy this year very much. I want to focus on Sevilla.
I could be stronger with my defending, I'm going to work on that I hope that it's a better year than last, which wasn't bad but I failed to take that little step forward and I hope to be able to do it here.
I want to have a good year because it's key for my career.
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