Koeman has been meeting with Barcelona players since his appointment and has reportedly told several players to find other clubs, including Luis Suarez.
Griezmann, however, was told he was a vital part of Koeman’s plans and Eric Olhats claims he then decided he would stay at Barcelona.
‘Before the disaster vs Bayern, Antoine wanted one thing: to leave,’ Olhats told RMC Sport.
‘He felt like he was no longer part of the plan, that things couldn’t continue like that.
‘He was seriously looking at it. Then, there was what we know happened and a conversation with Koeman reassured him, that he was part of his plans, that he considered him as an important player for the future.’
Griezmann only joined Barcelona from Atletico Madrid last summer after a long transfer saga.
The Frenchman became a superstar playing as a second striker at Atletico and Koeman confirmed he intended to restore Griezmann to his favourite position.
‘With all due respect he is not a traditional winger, so you have to play him in his own position where he is used to playing, in a role that suits him and where he can showcase his abilities,’ Koeman said about Griezmann.
‘You have to know your players as a coach and ensure you get the best out of them.’
Barcelona chiefs hope to convince Messi to reverse his decision, but the Argentina star is reportedly keen to join Manchester City.