Eric Olhats believes Barcelona should play Antoine Griezmann as an out-and-out striker to help him find his best form.
Olhats has worked with Griezmann and his family since he was 13 years of age with Real Sociedad, though split from the camp last year.
"Antoine has developed as a striker in the attacking axis," he told L'Equipe.
"He is good in that position, which is also that of (Lionel) Messi. I guess it must be difficult for (Barca coach Ernesto) Valverde to play Griezmann on the wing."
Olhats added: “Tactically he has gone from a very special 4-4-2 in Atlético to a 4-3-3 in Barça. This has changed everything and you need to find your place in Barça."