Force India have said that they want to keep both of their current drivers for 2018.
"We'll do everything in our power to keep both drivers," he told Speed Week.
"We are in the enviable position of having a driver duo that is as good as the top three teams, and we need them if we want to keep our fourth place in the championship in 2017."
Indeed, he said that other teams have been sniffing around at both Perez and Ocon.
"Yes, our drivers are clearly in demand," said Fernley, "and for good reason - they are not average drivers. Luckily Esteban is with us for three years.
"And I don't get the impression that he wants to go somewhere else either. He does not forget that we gave him the chance that others did not want to give him, including Renault."
As for Perez, Fernley admits that the Mexican is always sought after by other teams, but Force India has the advantage of being one of the most competitive midfield teams.
"There is always an alternative for him, but I think Checo is happy with us," he said. "He knows that we can offer him the most competitive car in the midfield."
Force India are currently fourth in the team rankings.