Sebastian Vettel has played down the decision by Red Bull Racing to change his chassis ahead of the Spanish Grand Prix, insisting the process is 'not unusual'.

The defending champion has endured a trying start to the season, dictated by a disastrous pre-season testing programme and being unable to exploit the same speed from the RB10 as new team-mate Daniel Ricciardo.

Ahead of the first European round of the 2014 F1 season, Vettel will revert to a chassis used during winter testing, primarily to provide a back-to-back comparison to the outgoing car.

With this in mind, the German is relaxed about the move and is hoping this weekend's race will allow the team to unlock more of the car's potential.

"I think it's not unusual to change chassis, generally. Obviously if you change, you change to a new one, but we decided, as I said before, to change back to an older chassis just to make sure nothing is wrong. Just to see, or basically change the things that you can, to have a reset and try again.

"We don't think that there was anything wrong with the old chassis but nevertheless we decided to change, so if so we should get an answer this weekend.

"You can always look back and try to find something to complain about - or you can look forward. And I think in general we are trying to look forward to the next race. There's a lot more races this year to come and for sure we didn't score as many points as we hoped. But then again after winter testing I think we were in a very bad position.

"I think right from the first race it was probably better than what we initially expected. Lots of positives with Daniel's podium in Australia - which obviously got taken away - but then the podium in Malaysia showed that we are on the right track but knew, just reading the feeling inside the car that it's not yet where we want to be. And you also see that in the results."