The Brazilian took to Instagram shortly after his Barcelona teammate posted a slideshow of pictures of the pair representing the Catalan club over the years.
Alongside the clip Messi wrote: “It was an enormous pleasure to have shared all these years with you friend Neymar I wish you luck in this new stage of your life. See you tomorrow.”
Responding to the message, Neymar wrote: “Thank you brother … I’ll miss you mate!”
Barcelona announced on social media that boss Ernesto Valverde had allowed the Brazilian to miss training on Wednesday, suggesting he is all but set to leave.
Neymar was photographed driving to the club’s training ground moments before Barcelona’s official Twitter account posted: “Neymar is not training with the permission of the coach.”
The club later confirmed the player had informed them of his intentions to leave, adding that he would not be training with them for the foreseeable future.
Paris Saint-Germain have been strongly linked with a move for the 25-year-old throughout this transfer window.
They are seemingly prepared to pay his £199million release clause, despite some resistance from La Liga chiefs.
The deal would eclipse the £89million Manchester United paid for Paul Pogba, making Neymar the most expensive player in football history.
Barcelona released a statement earlier today revealing the player and his father had handed in a transfer request.
The statement read: “The player Neymar Jr, accompanied by his father and agent, has informed FC Barcelona this morning of his decision to leave the club in a meeting held at the club’s offices.
“Faced with this position, the club has informed them they refer to the buy-out clause of his existing contract which as of 1 July totals €222million which will have to be deposited in its entirety.
“Furthermore, in reply to the claim for the contract extension bonus, the club has once again made it clear that the amount remains deposited with a notary until the case is resolved.
“The player remains under contract at FC Barcelona but with temporary permission to not take part in training sessions.”