Giedo van der Garde has admitted to surprise at his inclusion in Caterham’s test plans this week.
Originally, the former Lotus team scheduled the four days of the Jerez session to be split evenly between Heikki Kovalainen and Jarno Trulli.
Italian veteran Trulli, however, has been shunted from Thursday’s schedule in favour of van der Garde, the Dutch former GP2 driver who has been signed as Caterham’s 2012 reserve.
"We are very curious to see him at work in our new car," said team chief executive Riad Asmat, according to Dutch-language reports.
"I am surprised and delighted with this opportunity," added van der Garde, who is backed by the sponsor McGregor.
"I am fit and ready to get the best out of the car and myself," he said.