Hamilton teammate to be known in one week
The British team's Spanish test driver said in Madrid that he is one of the candidates, but declined to name the other, according to the news agency EFE.
"Right now the seat is between two and I suppose we will know soon who will be the second driver; less than one week," de la Rosa said.
It is widely believed that Heikki Kovalainen, who was left out of Renault's race lineup for next year after debuting in 2007, is also in contention for the seat. McLaren chief executive Martin Whitmarsh recently mentioned Gary Paffett as another possible contender.
De la Rosa refused to rate his own chances of landing the job.
"I do not know," he insisted, "and I prefer to be cautious and not have illusions. There were many suitors and now not so many. I assume that everything will be known within a week.
"Last year with Fernando Alonso coming I was aware that having two Spanish drivers would be difficult, but this time it is not the case."