Barca have told Perez to find himself a new club this week and is the subject of negotiations with Roma.
However, Roma chief Gianluca Petrachi insists they won't sign Perez if Barca continue to demand the inclusion of a buy-back clause in the deal.
He explained, "Roma wants to show that it has its own strength and that it is not the branch of anyone, so there will be no buyback clause.
"The negotiation has begun and the relations between both clubs are excellent. Personally, I am optimistic, although I don't like to talk until there is something closed."
Petrachi also confirmed talks have begun with the player's agents: "We will try to convince him of the sports project we offer him."