Jenson Button described the Canadian Grand Prix as a painful experience for McLaren and one that underlined the depth of its plight.
At a circuit where the team had won for the past three seasons, McLaren failed to score a point. Sergio Perez and Button finished a lap down in 11th and 12th, halting McLaren's run of 64 consecutive points finishes.
The two drivers opted for alternate strategies, but Button said their finishing position proved that no tactical masterstroke could have made up for the car's lack of speed.
"It was quite painful out there today. We've got a long way to go," he said. "I think we proved today that it didn't matter what we did in terms of strategy.
"I've never been so pleased to get out of a car. It wasn't the best race for us as a team. We got easily lapped and it was like we were in a different category."
Button also questioned McLaren's handling of the race, suggesting it had stipulated too slow a target lap-time when he rejoined after his sole pit stop.
"We tried to settle in to a pace on the prime tire in the second stint that was way too slow," he said. "We've got to look into why we thought that lap time was quick enough. We've just got to get our act together and improve."