Retired British driver David Coulthard [ Images ] is on standby for a Formula One comeback if either of Red Bull's drivers are unable to race in the first two Grands Prix of the season, the team said on Wednesday.

A spokeswoman said the 37-year-old Scot, in Melbourne [ Images ] as a pundit for BBC television, was their official reserve driver for Sunday's Australian season-opener and the following race in Malaysia.

New Zealander Brendon Hartley, a Red Bull junior driver, had been lined up for the role but the 19-year-old was unable to obtain the mandatory super-licence.

The team said nothing was confirmed after Malaysia.

Coulthard retired at the end of last season after a 246-race career that brought him 13 wins for Williams and McLaren [ Images ] over 15 seasons in the sport.

Red Bull's regular drivers are Australian Mark Webber [ Images ], who broke his leg in a cycling accident in November, and Germany's [ Images ] Sebastian Vettel [ Images ].