The 25-year-old has spent the past two seasons on loan at the Brazilian outfit, but as it stands Denilson will return to his parent club in the summer.
Lopes told ESPN Brasil: "There are still more than 60 days left on his contract, so there are a couple of points to take into consideration.
"The first point is that we are interested in the player and the second point is that we must deal with this situation closer to the end of the deal. If we do it too early, it will end up costing us more money."
Denilson has not played for Arsenal since 2011.