Barcelona lost Neymar to PSG in the summer with the Brazil international swapping La Liga for a new challenge in Ligue 1.
However, he remains close to the squad and visited them earlier in the season, with Messi among his closest confidants.
The Argentina international still possesses a good relationship with Neymar despite his controversial decision to leave Barcelona for PSG.
And Spanish outlet Don Balon say that the Brazilian has been told by Messi that Barcelona are closing in on the signing of Gremio ace Arthur.
The 21-year-old is billed as one of the brightest prospects in Brazil.
Recent reports have suggested that Barcelona have been quoted a huge £44million to sign the player.
Arthur was recently snapped in a Barcelona shirt in a move that did not sit well with Gremio fans.
Yet Don Balon claim that Neymar is now aware that a deal is all but done.
Only small details are yet to be ironed out before the transfer goes through.
Neymar is said to be on speaking terms with the player and texted him days ago to congratulate Arthur on firing Gremio to the Copa Libertadores.
Meanwhile, speaking last month, Barcelona boss Ernesto Valverde outlined a desire to keep transfer plans secret.
“If there is interest in signing any player in January who’s not here at the moment, I wouldn’t like it to be broadcast all over the world,” Valverde said.
“I’m more interested in [B-team players Carles] Alena, [Jose] Arnaiz and [Oriol] Busquets than other players at other teams.”