“You have great drivers like Narain Karthikeyan and Karun Chandhok, who are full of confidence and have good potential. Karun is racing in GP2.

“But then it would be difficult to say how they would perform if you put them in the (F1) car,” Coulthard said.

“When a driver moves from one form of racing to another, it becomes altogether difficult to comment how he would perform in the new stage,” said the 38-year-old former ‘Red Bull’ racer.

Coulthard was also not ready to buy the sentiment that Vijay Mallya-owned F1 team Force India should have given a chance to Chandhok after Giancarlo Fisichella switched loyalty to Ferrari team in the middle of the season.