Heikki Kovalainen insisted that Caterham had underperformed after being outpaced by rivals Marussia in qualifying for the United States Grand Prix.
Kovalainen endured his worst qualifying performance of the season as he was only able to post the 22nd time, with Vitaly Petrov only one place ahead in the sister car.
It meant the two Caterham drivers failed to beat their Marussia rivals and Kovalainen said the plan the team had simply hadn't worked.
"We underperformed today, it's really that simple,” he said. “We went with a plan that didn't work and unfortunately both Vitaly and I weren't able to get enough heat into the tyres to get the best out of them, or manage the traffic well enough to get a clean lap in.
“Tomorrow's another day so now we need to regroup and have a better performance in the race than we did today."
Writing later on his Twitter
feed, Kovalainen said his aim for race day was clear.
“We will beat Marussia,” the Finn wrote. “We are the better team.”
Despite out-qualifying Kovalainen, Petrov said he was also disappointed with Caterham's performance – with the yellow flags brought out when Narain Kartikeyan's HRT ground to a halt also not helping.
"Quali obviously didn't go how we wanted it to,” he said. “I had traffic issues on every lap and wasn't able to put a clean lap together, but even without that we've struggled with the tyres here all weekend and that showed today.
“It was bad timing for us that the HRT stopped on track just when Heikki and I were on our quickest laps and having been stuck behind them, but you can't plan for that so we need to put today behind us and hopefully we'll be better tomorrow."