Sauber waiting on Ferrari Raikkonen/Leclerc call for '19 F1 line-up

The Swiss outfit has free choice over one of its seats but, as part of the team's title-sponsorship deal with Alfa Romeo, Ferrari has the right to nominate who takes the other.

It is understood that a decision on this front only has to be made by October 15.

Ferrari is currently finalising whether Raikkonen or will be Sebastian Vettel's team-mate next year.

Once the call on Raikkonen is made, the Italian team will then decide whether Leclerc stays at Sauber or is moved to Haas, with Antonio Giovinazzi then being slotted in as his replacement.

While that situation remains fluid - especially with growing indications that Raikkonen will stay on board - Sauber team boss Fred Vasseur said it is better for his team to hold back before choosing its second driver.

Asked by Autosport if the team would wait on Ferrari or decide its other seat first, Vasseur said: "We could [choose first], but the line up is important.

"The combination is an important point and it is always much better [to know who both are]."

Pushed on whether he was pressuring Ferrari to make a call as a result, Vasseur added: "I am not pressuring Ferrari at all, I think you are pressuring Ferrari much more than I am.

"I don't know when they confirmed Kimi last year. I think it was much later into the season... it is not because [Daniel] Ricciardo moved that everybody has to take the decision within a week."

Vasseur still thinks it is early in the year for Sauber to need to sort its drivers, and said historically things have been decided much later.

"If you look at the past, we are quite early into the season," he said.

"If you look at last year and the years before, at this stage of the season more or less nothing was done.

"I don't know what happened during the summer, if there was a mosquito or something like this, but [the market] got crazy.

"We have to take it calmly.

"The most important thing for me is to stay focused on the current races, Spa and Monza are two important events for us. I am trying to keep the teams and drivers in the right way, and it is not easy."

Asked if Sauber could even wait until the winter to finalise its line-up, Vasseur said: "When a big part of the pieces of the puzzle are on the table at one stage, you have to close the deal."