Felipe Massa accepted responsibility after he exited qualifying for the Russian Grand Prix during the second knockout segment.
Williams had been among the frontrunners but Massa could manage only the 15th fastest time during Q2 and will start the race from that position on Sunday.
"I made a mistake at turn eight in my first timed lap in Q2, and then in my final two attempts I came up against a lot of traffic which lost me a lot of time," he said.
"On my final run my tyres were gone at the rear and that was the end of my chances. It’s a shame and I’m very disappointed, but I have a quick car around here so we need to have a good strategy and use our pace to move up into the points tomorrow."
Team-mate Valtteri Bottas enjoyed a more productive day as he qualified in third place.
"I felt very good in the car all day and managed to get in a rhythm quickly and put in consistent lap times despite the limited number of laps we had completed in practice," he said.
"Tomorrow is where it really matters but I have put myself in a very good position to capitalise."