Kimi Raikkonen was the centre of attention during Thursday's press conference ahead of the Singapore GP, and unsurprisingly he kept his answers to a minimum.

On Tuesday came the unexpected news that the Finn will remain in Formula 1 next season but with Sauber, performing a straight swap with Charles Leclerc who will take Kimi's seat at Ferrari.

While that has led to criticism from some, with pundit Martin Brundle suggesting the 38-year-old should have retired, Raikkonen insists the only opinion he thinks about is his own.

"Because I want to go. Why do you try to make it so complicated?" he responded when asked what made Sauber a desirable choice.

"I don't know anything more than you guys [beyond] purely where they have been finishing. I don't know what will happen, nobody knows what will happen next year.

"I don't care about what others think. As long as I am happy with my own reasons, it is enough for me."

The increased likelihood of Leclerc's move only came about at Monza, when it emerged former chairman Sergio Marchionne had already signed a race contract with the Monegasque.

And it was only after that point that Raikkonen made contact to his former team.

"I knew, and obviously I know people there from the past and basically it started after that," he explained. "I don't think it has always been there [the desire to return].

"Obviously you never know here what will happen. I wouldn't say there were plans for a long time that this is going to happen."

There has been suggestions a possible motive included future investment by Kimi into Sauber, though again he refused to comment decisively.

"I signed my contract as a driver and I hope I stay there as a driver," he said.

"Who knows what happens in the future or two years. There is always speculation, but I don't have any contract about that."