Fernando Alonso admitted his frustration after he stopped on circuit during qualifying for the Brazilian Grand Prix, as McLaren's woes performance and reliability woes continue.
Alonso, who had to park his MP4-30 during second practice, pulled off the circuit during Q1 with a loss of power and watched the remainder of the session from the side of the track.
"This is a tough period," he rued.
"After I didn’t take part in the Mexican Grand Prix, and then missed out entirely on qualifying here in Brazil, well, there’s a degree of frustration, obviously.
"But we understand our situation, and we need to learn from all our mistakes and put everything in place so as not to repeat them next year.
"I think all our weaknesses are being identified, however. The actions we’re taking are logical and sensible, so I’m still optimistic, even though here and even Abu Dhabi are going to be difficult for us."
Team-mate Jenson Button managed to complete the session, but was unable to escape from Q1 and will start from 16th place.
"It’s been a tricky weekend, and I’ve struggled with the car," he conceded.
"Having said that, it began to work much better in qualifying. It was much more enjoyable to drive than it was this morning, when we had less aero balance.
"Moreover, the car is definitely set up for the race; I still don’t know how competitive we’ll be, because deployment is going to be a big issue here, but we’ll give it a go and we’ll see what we end up with.
"I’m hoping for a wet race. If it rains it will open up more opportunities, and we’ll hopefully capitalise on it. I’m looking forward to it."