Barrichello is second behind Schumacher

The Williams team have picked up just 30 points in five races with Juan Pablo Montoya and Ralf Schumacher struggling to make an impact.

But Barrichello noted Williams were in a similar position to this last season.

"We should remember that last year, Williams did not really get on the pace until they won in Monaco," the Brazilian told Ferrari's website.

"So we should definitely not discount them and now it is clear that, in terms of pure speed, BAR are the closest to us, with Williams and Renault not too far behind."

Montoya's win at the Monaco circuit last year began a run of three wins in the next five races for Williams, who ultimately had to watch Michael Schumacher win the world championship for Ferrari for the fourth successive year.

Schumacher leads this year's drivers championship, having won all five races.