Reigning world champion Sebastian Vettel has conceded that Red Bull is not the team to beat ahead of next weekend's Australian Grand Prix.
Red Bull has endured a problematic pre-season testing programme with its RB10 as overheating problems and issues with the Renault power unit restricted its running.
Vettel echoed comments made by team principal Christian Horner, who admits that Red Bull is not in a position to challenge Mercedes.
"It’s great to be starting the season next week," said Vettel.
"We didn’t do as much running as we would have liked in testing this year, so we have work to do in Melbourne, but it will be good to get to the first race.
"It’s hard to know where we are; it’s fair to say that we’re not the favourites to win and we have to catch up with others that have completed more mileage, but we’ll do our best with the great people that we have working for the team.
"We have achieved a lot together and I know everyone is working flat out as normal. It’s a good event to start the season and there’s always a great atmosphere."
Vettel's new team-mate, Australian racer Daniel Ricciardo, is expecting a busy time at his home event.
"It’s great that Australia has a grand prix and a source of pride that it’s everybody’s choice to kick-start the season," he said.
"If we went to Malaysia or Bahrain for the first race then I’d be able to ease into my career with Red Bull but in Australia I assume the weekend will be right up there in my face! I’ll enjoy it and hopefully use the positive energy of the crowd to give me a good result."