Robert Kubica admits he was "surprised" when Ferrari decided to sign up Carlos Sainz as a replacement for Sebastian Vettel next year.

"If the relationship was not good and not getting better, then it's better to make a decision," the Polish driver told Corriere della Sera.

"I was a little surprised but I do not think the decision was taken recently. Ferrari always has precise plans and money has nothing to do with them," Kubica added.

Indeed, it is believed that Kubica, now 35, was heading to Ferrari for the future when he suffered his permanent arm injuries in a 2011 rallying crash.

"I had it done with them," Kubica admits, before joking: "Now I even avoid buying red cars."

As for Ferrari's latest decision, he said: "Sainz is a bold choice.

"He has never driven at the front and that could be a problem when they are chasing big results. Bottas or Ricciardo would have been safer options."

Kubica is also impressed with Max Verstappen.

"I think Max is very smart and ready to win a title," he said. "It remains to be seen how he will behave when he is doing that, but I would immediately bet on him being champion."

Finally, Kubica said his return to Formula 1 with Williams last year may have had a different outcome if Bernie Ecclestone had still been in charge of F1.

"Eight years of absence is a lot," he said. "Many drivers, even many journalists did not even know me, and even those who manage the sport have not done it all their lives.

"If Ecclestone had been there, things would probably have been different."