The 28-year old striker is being tracked by Tottenham and Liverpool but Salvo says a £25million release clause bid must be lodged by the aforementioned date otherwise the player will stay at the Mestalla.
"If any club wants our striker they are obliged to accept our conditions. And the price on the market has a clause," he said.
"Until August 3, we accept that a deal may happen and we can negotiate. But after that date, he will not leave us."