Mark Webber has copped a five-place grid penalty for Sunday’s Belgian Grand Prix following an unscheduled gearbox change.

Red Bull Racing notified the FIA that Webber’s gearbox would need to be change midway through a soggy Friday practice run at the Spa-Francorchamps circuit.

The Australian goes into the Belgian race second on the championship, 40 points behind Ferrari’s Fernando Alonso with nine races remaining.

Webber’s penalty will come as a boost to his teammate Sebastian Vettel, who won from pole at Spa last year and is just two points behind Webber on the title standings.

The news came on a tough opening day for the drivers at Spa with heavy rain severely hampering the track time available in Friday’s three practice runs.

Webber finished fifth fastest in opening practice but didn’t run in the day’s second session, with Kamui Kobayashi proving to be both the bravest and fastest driver on the day.

Kobayashi’s two minutes and 11.39 second best lap proved enough to top the timesheets ahead of Pastor Maldonado, Daniel Ricciardo, Jean-Eric Vergne and Webber.

“It’s a shame because we love Spa and it would be nice to do some more laps, but in the end you can’t really learn much in these conditions,” Webber said.

“We some info from free practice one, but you can’t race when there’s so much standing water on track and you probably wouldn’t qualify in this so in the end we just put the car to bed tonight and come back tomorrow.”