Pastore is up for sale at the Rosanero for €50 million.
"If the right offer arrives then he will go," Rosanero sporting director Sean Sogliano told Sportal. "The work of his agent will prove fundamental.
"Before we can complete the signings of a few players, this situation has to be resolved and quickly seeing as pre-season will start soon.
"It's hard to predict what will happen with regards to new players, but we are certain that we need to reduce the size of our squad."