Williams will need to replace the fuel system on Felipe Massa's car after a pressure problem saw the Brazilian driver qualify 18th fastest for Sunday's Russian Grand Prix.
Massa saw promise after his good Friday practice performance, but was struggling for power in Q1 and failed to progress further.
The 33-year-old revealed that the issue can be resolved in time for the start of the race.
He told reporters: "I went out and the problem was there since I went out of the garage. They were trying to change the other modes and the other buttons to see if we can go back to the normal working, but we could not.
"It was a mechanical problem, so we needed to change the fuel pump and they are doing it now. There was nothing really to do.
"I think I have possibilities to overtake, yes. It's a track with two long straights, so there is a possibility. It would be much better to start in the right place because then the race is much easier and you can be on your pace all the time. We will see what we can do tomorrow, but I still believe that we can do a good race."
Massa's teammate Valtteri Bottas will start from third on the grid, behind the Mercedes pair of Lewis Hamilton and Nico Rosberg.
