Force India deputy team principal, Bob Fernley makes clear that Esteban Ocon cannot be used as Mercedes stand-in.

Though a prominent member of Mercedes junior programme, Force India is adamant that should the German team encounter an issue this season necessitating a substitute for either Lewis Hamilton or Valtteri Bottas, the Frenchman would not be released.

"Absolutely not," deputy team principal Bob Fernley told Autosport. "He's a Force India driver for two years, and that's it.

"He can't substitute one of their drivers," he added, "but if they were asking him to test, I'd be quite pleased to let him do that."

Ocon, who made his F1 debut in 2014 when he drove the Lotus in FP1 in Abu Dhabi, subsequently drove the Force India at the post GP test. He drove the Force India again at the post Spanish and Austrian GP tests in 2015 though it was Renault he joined in 2016 as reserve driver alongside his DTM commitments.

When Rio Haryanto's funding dried up at Manor, the French star was handed the seat at the Banbury-based outfit alongside fellow Mercedes junior Pascal Wehrlein.

On a two-year contract with Force India, Fernley insists that while Ocon's stint with the team is essentially a 'stop gap' placement before he moves on to greater things, this will not affect the team's attitude towards him.

"We could have a situation with another driver where we've got him for two years, and then he decides to move on," he said. "No matter what you do I think the answer is you have to optimise the performance from both the team and driver point of view while you have them.

"If you're performing at the top, you limit their desire to want to change," he concluded.