When Neymar swapped Barcelona for Paris Saint-Germain, it's fair to say it left the football world in a state of shock.

The Brazilian superstar became the most expensive player in the history of football following the €222 million move and left a gaping hole in the Catalan side's frontline.

Neymar made a fantastic start to life in France with a goal and a very impressive assist during his PSG debut on Sunday as the Parisians eased past Guingamp 3-0.

With the massive windfall the club has received from the sale of Neymar, the Blaugrana know they have to act fast to improve their squad before the transfer window slams shut - especially after losing to Real Madrid in the first leg of the Spanish Super Cup on Sunday.

The first man to join the ranks is not a direct replacement for Neymar - it's former Spurs flop Paulinho.

The Brazilian international, 29, had been playing for Guangzhou Evergrande in China and moves to the Nou Camp for around €40 million.

As international teammates, Neymar and Paulinho have obviously grown pretty close in the past and the most expensive player in the world had a message for his friend after securing his dream move.

"Brother, every success in the world for you .. I hope you are very happy how I was there.

"I love you too," Neymar wrote.

As you can see by the comments on the post, plenty of Barcelona fans are unhappy with Neymar. Here's just some of the comments below:

New manager Ernesto Valverde has had a difficult start to life as Barcelona manager, but he believes the El Clasico scoreline wasn't a fair reflection of the play.

"They scored three goals, but this was a game in which we played well and had chances.

"Reaching their danger zones isn't all that matters, as you also need to hit the target. I don't believe that we're lacking goalscoring ability, but they were more clinical.

"They caught us in a one-versus-one situation and then scored one wonder goal and then another to make it 3-1. It was an even game and they had a strong central midfield, which made playing inside difficult.

"Their second goal really hurt us. We congratulate them and we will try to improve for the next match."