Vandoorne impressed greatly when he scored on his Formula 1 debut for McLaren at the Bahrain Grand Prix, as a stand-in for the injured Fernando Alonso.

McLaren has an option on Vandoorne for next year, but it will need to take that up by its September date if it is not to risk losing the Belgian to another outfit.

With that option meaning Vandoorne cannot go elsewhere before then, McLaren has made it clear that there will be no confirmation of its plans until then.

Speaking to Motorsport.com, Boullier said: “Because we don't want to destroy this year, we don't want to talk before September.

“If we start to speak before then, it is going to make the drivers' head go wrong.”

Open to youth

Boullier is adamant that McLaren has not made the final decision on whether or not it wants to promote Vandoorne, but has suggested that there could be benefits from getting a young driver rather than sticking with an experienced one.

“It depends which stage you are in with your restructuring of the team and the path to win,” explained Boullier.

“You need experience, but you also need youth because it means new blood, and also pushing as well the experienced driver [team-mate] to not be in a comfortable zone.”

When asked if it was a big problem having to make such a complicated choice for next year, Boullier said: “It is not a problem. Not a problem at all...I have the best possibilities in my life, two world champions and the most promising young driver.”

Interview by Jacobo Vega