Following weeks of speculation, Mattos has revealed that contact has been made between the two clubs, but Palmeiras would rather keep hold of the Colombia international until the end of the season.
"It's true that Barcelona came for Mina with another offer but also that Palmeiras want Mina to stay here," he told reporters. "We are going to wait for him to arrive in Sao Paulo and we will talk.
"If Palmeiras is satisfied with any situation so that he leaves before, we will do it. Otherwise, he will stay with us."
Barca will reportedly pay a fee of around £10.7m to sign Mina - £1.7m of which will be in performance-related add-ons.