Paulinho bade Guangzhou Evergrande an emotional farewell but kept the door open on a possible return as he exited for Barcelona.

Barring a problem with his medical, the 29-year-old Brazil international will be unveiled by the Catalan giant on Thursday after agreeing a $47 million four-year deal.

Following a lackluster stint with Tottenham, Paulinho has rejuvenated his career in China and he was understandably sad to leave.

"Thank you Guangzhou Evergrande for this two years and a half," said Paulinho in a video on social media.

"I have very, very, very, much enjoyed here. Thank you for these fans. Thank you, the president, the staff and also the players. I hope one day I will come back. Thank you, everyone! Bye bye."

Reports in China have suggested that Paulinho has agreed with Liu Yongzhuo, the vice-president of Evergrande Group, to consider returning to Guangzhou after three years in Spain, with a view to ending his career with the Guangdong province club.

If Guangzhou's recent history is any indicator, the fans have reason to believe it is not an idle promise after another Brazilian, Muriqui, returned to the club after three years away last month.

Barcelona agreed to meet Paulinho's release clause after weeks of negotiations with the Chinese Super League club. Guangzhou Evergrande's Brazilian coach, Luiz Felipe Scolari, confirmed the transfer with Folha de S.Paulo newspaper over the weekend, and that the midfielder will not be available for Sunday's league match against Henan Jianye.

Paulinho is Barca's first new recruit since Neymar departed Camp Nou in a world-record $264 million transfer to Paris Saint-Germain.

And PSG's new golden boy was quick to wish his Brazil teammate luck with the swtich.

"My friend, all the success in the world for you. I hope you will be very happy there, as I was. I'm with you," Neymar wrote on Instagram.

Paulinho has helped Guangzhou to two CSL titles and an Asian Champions League trophy in the past two years. This season he was scored 12 times in 29 matches in all competitions for the club.

However, a lack of success in Europe has left some Barca fans dubious of the move.

After spells in Lithuania and Poland as a teenager, Paulinho moved back to his home country with Corinthians before being snapped up Tottenham for around $22 million in 2013.

However, after two lackluster years at White Hart Lane,Spurs offloaded him to Guangzhou for $13 million.

Paulinho's revival, though, has not just been consigned to the CSL, with Brazil beneffiting massively from his upturn, and he notably netted a hat-trick in a 4-1 win away to Uruguay in World Cup qualifying in March.

Paulinho's former Spurs boss Andre Villas-Boas, now Shanghai SIPG's coach, believes the transfer is a huge boost for the CSL.

"Because Paulinho's come here, he's done ever so well and now he has a transfer to one of the biggest clubs in the world," said Villas-Boas.

"I think it shows that the big clubs are also looking at our league. It's a reflection of the players and the quality of work that is being done here."

Agencies contributed to the story