"They can negotiate with whoever they like," he said.
"But what a coincidence... when Barca are negotiating for a player, another club appears out of the blue - it's always the same.
"We complete signings when the price is reasonable. And the story of Cesc is what it is. The player has said both publicly and privately that he wants to play for Barca."
In any case, Oliver says he in unconcerned because there has been a lack of signings across Europe so far this summer.
"There has only been one important operation up until now and that was David Villa's signing for Barca. That's why we won't rush and we won't sign anybody paying an exorbitant sum," he said.