Williams has delayed the announcement of its drivers for 2011 because the British team is considering whether or not to retain Nico Hulkenberg.
That is the suggestion of Rubens Barrichello, amid widespread expectations the Brazilian veteran has now signed a new contract to stay with the Cosworth-powered team next year.
"On my side I think it was an easier decision," the 38-year-old is quoted by Brazil's Globe Esporte.
"They (Williams) are waiting. I think they are analysing the Nico Hulkenberg situation in order to do it (an announcement) together for next season," explained Barrichello.
"My part is done, all that is left is the papers to make it confirmed. That I will be with Williams in 2011 is 100 per cent," he confirmed.