Daniel Ricciardo has admitted that Red Bull is not up to scratch, with just three days of pre-season testing remaining.
Ricciardo set the seventh quickest time on the first day of the final pre-season test in Bahrain but once again lost out on track running as his RB10 developed an exhaust problem.
The Australian driver completed 36 laps.
"It's still not enough laps but we are going in the right direction," Ricciardo told reporters after the first day of action.
"Last week, we were doing stuff we wanted to do in Jerez, and this week we are doing stuff we wanted to do last week. So we are definitely not up to scratch in terms of where we want to be.
"In terms of our power, we definitely made a step forward this morning."
"If we can work on this over the next three days, it would definitely help us for Melbourne. We are staying positive and optimistic. Each day we can learn a lot and there are still a fair few of them before Melbourne so we'll be alright."
Ricciardo emphasised that it is too soon to dismiss Red Bull.
"It's clear that we are probably not going to go to Melbourne and dominate, but it's still early days."
Ricciardo will remain in the RB10 on Friday before handing over to Sebastian Vettel for the final two days of action.