Replacement gearbox: Sebastian Vettel's Red Bull broke down in qualifying

The World Champion was already due to start down in tenth place for Sunday's Barcelona race after the gearbox glitch struck at the start of Q3 before he had chance to complete a timed lap in the final session.

Despite Vettel expressing hope that the unit would not need to be changed for the race, Red Bull confirmed on Saturday evening that a gearbox switch would be required.

With the Sporting Regulations mandating that gearboxes have to last for six consecutive races in 2014, Vettel's out-of-sequence change incurs the standard drop, meaning he will start 15th - his lowest position since the 2012 Abu Dhabi GP.

The 26-year-old has endured a nightmare weekend at Barcelona having already lost most of Friday's running because of an electrical fault, and speaking prior to confirmation of his Sunday grid demotion, a downcast Vettel admitted: "Of course it's disappointing and by now it's a bit boring because we've had all sorts of problems."

With Red Bull having been usurped by Mercedes at the top of the F1 tree following F1's rules reset, Vettel, who is also facing an increased intra-team threat from new team-mate Daniel Ricciardo this year, is already 46 points off the championship lead.

Mercedes' front-row lock-out in qualifying makes it likely that the reigning champion's points deficit will stretch beyond the equivalent of two race victories by the end of Sunday's 66-lap race.