Atletico Madrid star Griezmann has been heavily linked with La Liga champions Barcelona amid his reported €100 million (£87m/$117m) release clause.
The 27-year-old France international, who helped Atletico to Europa League glory this season , revealed he will decide his future before the World Cup in Russia .
Barca winger and international team-mate Dembele said he is excited by Griezmann’s potential arrival.
“We haven’t talked much about this [transfer] with Antoine,” Dembele said. “If Antoine comes to Barca, it would be something exceptional.
“He’s a great player, a great striker, I think he’ll help us be better.”
Griezmann – gearing up for the World Cup where France will meet Australia, Peru and Denmark in Group C – scored 29 goals for Atletico in 2017-18.
Dembele, meanwhile, endured a difficult first season at Camp Nou following his big-money arrival from Borussia Dortmund.
Hampered by injury issues, Dembele scored three goals and tallied six assists as Barca won La Liga.
Reflecting on his maiden campaign, the 21-year-old said: “A first season with many injuries. It’s a tough season. I’ve had a lot of injuries. I had to learn a lot. Despite everything, I still have confidence. The group, the team and the president trust me. We will see what happens in the coming seasons.
“I’ve made progress in the tactical aspect. But also in defence. I defend much more in Barcelona. Even if we have the ball a lot. It’s important not to lose a ball. It’s rare for the team to lose the ball. You have to be careful. I have to defend a lot because we are all united.”
