Reports claim Rubens Barrichello is under pressure to retain his seat at Williams into F1 2012 from Force India's two Germans, Adrian Sutil and Nico H?lkenberg - as the Brazilian veteran bemoans the 'confusing' development of the Cosworth-powered FW33.

Barrichello has tallied just four points this year - courtesy of back-to-back ninth-place finishes in Monaco and Canada - and has not once made the top ten on the starting grid in the opening eleven races. A more conventional set-up seemed to help the 39-year-old's plight at the Hungaroring last weekend, but the fact remains that 'Rubinho' has been out-qualified six-five thus far by unrated rookie team-mate Pastor Maldonado, a man who arrived in F1 dogged by 'pay driver' rumours.

With Williams ostensibly happy with Maldonado's consistent improvements - not to mention the financial benefits he is able to bring to the Grove-based outfit from Venezuelan state-owned petroleum company PDVSA - Barrichello's future at the team has been called into question.

Next year would mark the eleven-time grand prix-winner's 20th consecutive campaign in the top flight, but speculation suggests he could be denied that marker by either former team-mate H?lkenberg - who ironically was forced to make way for Maldonado this season - or Sutil. Certainly, Barrichello is becoming increasingly frustrated by progress - or rather, a distinct lack of it - at Williams.

"Our car cooks the rear tyres," the most experienced driver in the sport's history is quoted as having said by German magazine Auto Motor und Sport, lamenting the fact that his car is invariably used in practice sessions to try out new parts. "The driveability of the engine is bad, and in slippery conditions it's even worse.

"No matter what we do, we can't make the tyre problem go away. Never have I wanted to be a test-driver. We are bringing too many new parts to the car - and only confusing ourselves."