Barca are favourites to sign Griezmann this summer, when his contract's buyout clause falls to €100m at season's end.
However, Diario Gol says Messi, while respecting Griezmann's ability, has concerns about his love of Real Madrid. Despite his Atleti status, Griezmann is a huge Real fan, according to friends.
And he has also told directors they should be focused on strengthening the defence, rather than adding another attacker like Griezmann. Messi now has a formal say on Barca's transfer plans courtesy of a clause in his recently signed contract.