Rubens Barrichello's future at Williams is not yet secure, team boss Sir Frank Williams has admitted.
Brazilian veteran Barrichello, 39, said this week that while he wants to drive the team's new Renault-powered car in 2012, he is yet to be offered a deal.
"Well, I can't say anything about our drivers until we have made up our own minds," confirmed Williams at Silverstone.
Barrichello also said this week that he is not ruling out a switch to a rival team.
Williams said he rates the winner of 11 Grands Prix "very highly".
"He is truly a treasure trove of information and experience and that's something that will not be thrown away lightly," he insisted.
Asked if Barrichello has performed well in 2011, Williams answered: "Yes, I think he has. I think if we had given him a better car he would have been very close to the front, if not at the front. He is a superb driver."