Kimi Raikkonen has cast doubts over whether he will spend the two years with Ferrari, saying he never said when he would retire.
The Finnish racer, who won the 2007 World title with Ferrari, is contracted to the Scuderia until the end of next season.
He recently stated that his Ferrari contract would be his last but when exactly that will end remains to be seen.
"I'm not worried," Raikkonen told Sky Sports F1.
"At Silverstone I said that I will stop when my contract finishes - I never said any year.
"I'll finish my career in a Ferrari; when it is, I don't know."