Brawn/Mercedes should have "fought" to keep the 2009 driver lineup for next season, according Rubens Barrichello.

The Brazilian veteran's teammate this year was the 2009 world champion Jenson Button, and together they collected 8 victories for the Brackley based squad as well as the constructors' title.

But Barrichello, 37, has switched to the Williams team, before Brawn was taken over by Mercedes and Button sensationally moved to McLaren to be Lewis Hamilton's new teammate.

Nico Rosberg has been signed for one Mercedes GP cockpit, and insiders expect the other to be filled by his German countryman Nick Heidfeld. Neither have won a grand prix.

"Honestly, if I was the owner of the team I would have fought to keep both (2009) drivers because of the work that was done during the season," Barrichello is quoted as saying at the Florianopolis kart race by Spain's Diario AS.

He however denied that he had to move to Williams, the last team of his mentor Ayrton Senna, because Brawn did not want to keep him.

"My decision was taken very early. It has been my childhood dream to race a Williams and for that reason I signed the contract quickly," said Barrichello, adding that Button's later departure was a "big surprise".

Source: GMM