It was during an international friendly in Australia
The two teams met in Melbourne in June and Paulinho says during the game, Messi told him to move to the Camp Nou.
“Willian and I were getting into position to take a free kick” he said.
“I was closer to the ball but it was Willian that was going to take it. Messi was further away.
“When Willian got into position to kick the ball I stayed behind and he [Messi] came walking towards me and said, “Come to Barcelona.” I looked at him and said, “If you want to take me, I’ll go.”
Source | Globoesporte
Paulinho also says that Neymar played a part in him opting to move to Barcelona from Guangzhou Evergrande in a €40 million deal.
“When the talks with Barca were going on, Neymar told me to come here and said that I would be happy here and I would like it,” he said
“He expressed encouragement so that my signing would be completed. He really helped me to come here and even though he ended up leaving, he told me that I would be happy at Barca.”
Despite all the criticism that greeted his arrival, Paulinho already seems to have silenced most of his doubters with three goals already this season.