Red Bull advisor Dr Helmut Marko has admitted that the Milton Keynes might not be able to make up their early season deficit after the defending Constructors' Champions' disastrous pre-season tests Spain and Bahrain.
During an interview with Red Bull's in-house Servus TV network, Marko admitted that Red Bull are probably months behind their title rivals in terms of development of their 2014 car.
"The season opener is coming at least two months too early for us," Marko said on the Sport und Talk programme.
"We are not where we should be."
The Austrian believes the biggest problem Red Bull has going into the season is that their title rivals had significant more time on the track during the 12 days of pre-season testing at Jerez and Sakhir.
"This is a very, very serious thing," Marko added.
"At the moment we do not know what (time) period we will need to catch up, or whether we will at all."
According to Mercedes chairman Niki Lauda, reliability is likely to be more important than speed during the season's first Grand Prix in Australia.
"I believe that half the field will not finish simply because there has not been the opportunity for enough testing," Lauda is quoted as saying.
While Red Bull's reliability issues are well known, they also struggled for pace during last week's final pre-season test in Bahrain.
Sebastian Vettel's fastest time was more than four seconds slower than that of pacesetters Lewis Hamilton and Felipe Massa, and its straight line speed is significantly less than that of the Mercedes-powered teams or Ferrari.
Engine manufacturer Renault, though, has taken some of the blame for that.
"Melbourne will be an anxious weekend," technical boss Rob White admitted.
"I hope we can support our teams and drivers to explore the performance of the car and allow the race to deliver its sporting verdict."