Rubens Barrichello has continued to admit his frustration at Williams amid uncertainty about his race seat beyond 2011.
Germans Adrian Sutil and Nico Hulkenberg are being mentioned as possible partners for the Brazilian veteran's current teammate Pastor Maldonado next year.
39-year-old Barrichello has in recent days been quoted as sounding impatient with Williams' recent experimentation at Grands Prix, insisting he has "never wanted to be a test driver".
Barrichello is now quoted by Italy's Corriere dello Sport: "It's an incredible situation. I don't know if I will continue next year in these conditions.
"In recent months we have brought too many aerodynamic parts, we could not test them completely and honestly you can't use a race for testing.
"We are confused, the team is shrouded in uncertainty."
Oxfordshire-based Williams is indeed set to change considerably for 2012, with technical chief Sam Michael replaced by Mike Coughlan and Renault instead of Cosworth to supply the engines.
There's the sense that we are not getting the results
"I think people needed to feel change," said chairman Adam Parr, with the famous British team only ahead of Lotus, HRT and Virgin in the constructors' championship.
"Everyone individually has been doing the best they can.
"But there's the sense that we are not getting the results and we needed a change, and people like what we are doing and where we are going," he added.