The 39-year-old is set to earn his final international cap when the world champions face Benin in a farewell friendly at the Estadio Monumental in Buenos Aires.
Writing on Instagram, the Brazilian reflected on his close friend's immense contribution to football as tributes pour in ahead of the eight-time Ballon d'Or winner's international swansong.
"Those who love football have taken advantage of you over the years… Today is your last match wearing the jersey of your team, your country, and I hope you enjoy every second," Neymar wrote on Instagram.
"It’s not just Argentina that thanks you, the world thanks you for everything you have done for football. Thank you for making me love football even more, it was an honor to have played against you and even more so to make history alongside you. Thanks Leo."
The pair enjoyed a hugely successful spell together at Barcelona, forming a formidable attacking trio alongside Luis Suarez, before later reuniting at PSG.
Despite the historic rivalry between Brazil and Argentina, Neymar and Messi have maintained a strong friendship throughout their careers.