Saturday 4 August at 04:35 : Aug.4 (GMM) Sauber is "laid back" about its driver situation for 2013.

That is the claim of chief executive Monisha Kaltenborn, despite reports Kamui Kobayashi has underperformed, Sergio Perez is on Ferrari's radar, and Caterham's Heikki Kovalainen could be joining the Swiss team next year.

"We are not worried," she told F1's official website, when asked about speculation Mexican Perez could be lured to a bigger team off the back of his good performances in 2012.

"Regarding the future, we are not under pressure and I am laid back about it," added Kaltenborn.

However, Japanese Kobayashi has failed to shine as brightly as Perez in 2012, triggering rumours Sauber could be on the lookout to replace him.

"I think that the results do not show the whole picture," Kaltenborn continued.

"I would say that some factors played for Sergio -- and some simply didn't work out for Kamui.

"But as we still have half the season to go, Kamui can go out and copy Sergio."