The Frenchman has not been able to hit the heights that were expected of him since his move to the Nou Camp in 2019.
Antoine Griezmann has been a fixture under new boss Ronald Koeman but has had a rather underwhelming season by his standards. He has only managed 10 goals in 32 appearances this season.
Jeremy Mathieu spoke to RAC1 about his compatriot's struggles at Barcelona and said (via Daily Mail):
"Griezmann is not at his Atletico level. Personally, in my opinion, it is a mistake that he came to Barcelona. At Atletico he was a very important piece and I don't know if he has that importance at Barcelona."
The 37-year-old was also quick to jump to the defense of his other compatriot, Clement Lenglet. The Barcelona centre-back has come under much scrutiny for his performances this season.
Mathieu sympathised with Lenglet and explained:
"I had a very bad time in my last year with Barcelona. I felt that the defeat in Turin [in the Champions League against Juventus] was my fault. But I don't understand why they went for me as there are 11 players in a football team. I felt alone in the dressing room. No one offered support. For me, that's not football. Everyone is killing Lenglet now, and I know what that's like. He has to try and be positive and to turn it around, and try his best."
Lenglet gave away a penalty in the dying moments of Barcelona's La Liga fixture against Cadiz, which lead to the Blaugrana drawing the game.
The 1-1 draw has left Barcelona at 4th place in the La Liga table, 8 points behind league leaders Atletico Madrid.
Barcelona are at a crucial stage of the season
Barcelona have an important two weeks ahead of them, as this stage of the campaign could define their whole season. The Blaugrana face Elche on Wednesday before travelling to Sevilla on Saturday for a La Liga fixture.
Barcelona will then host Sevilla in their crucial Copa del Rey second leg fixture before travelling to Paris, where they need to overturn a 4-1 deficit against PSG in the UEFA Champions League.
Ronald Koeman has his work cut out for him in the next few weeks and will need his side to step up if they are going to win any silverware this season.