Feb.26 (GMM) Sebastian Vettel on Tuesday stepped into David Coulthard's 2008-specification Red Bull cockpit as the Scot sits out the Barcelona session with an apparent neck strain.

Although a chipper Coulthard was spotted at the Circuit de Catalunya as the final test of the 2008 pre-season resumed, Vettel was asked to stand-in as the 36-year-old reportedly receives treatment for a light injury sustained whilst running in the RB4 on Monday.

It is expected that Coulthard will be back in action for the final day's running on Wednesday.

Toro Rosso's test programme is unlikely to be affected by the shuffle, as the Red Bull sister team is testing only with a single car in Spain this week.

On Tuesday, Sebastien Bourdais took over the car that was tested by STR teammate Vettel on Monday.

The Faenza based team will begin the 2008 season with a development of last year's car, before beginning with a similar version of the RB4 after the first few races.