Fernando Alonso has admitted that his teammate's introduction to Formula 1 this year has been "difficult".

Amid his push for a more competitive seat, the Spaniard has regularly pointed out that he is a long way ahead of the occupant of the sister McLaren-Honda, Stoffel Vandoorne.

Indeed, there are even question marks about the 25-year-old Belgian's future at the team, with boss Eric Boullier saying that Vandoorne needs to adapt more quickly to F1.

Alonso is quoted as saying by Spain's El Confidencial: "It is difficult and frustrating for him.

"He does not know most of the tracks, so he's learning the circuits and everything about Formula 1 but he can't test the car and often he is going into qualifying with no preparation.

"It is a difficult season for him and also for the team in general, and myself too. We hope to have a competitive car next year."

Alonso has two points so far this year, while Vandoorne has yet to get off the mark.