Daniel Ricciardo says Red Bull is still "not up to scratch" as the champion team's problems continued during the first day of the final pre-season Formula 1 test in Bahrain.
The Australian managed 39 laps -- only four fewer than he managed across the entirety of last week's test -- and set Red Bull's fastest time around the Sakhir circuit so far this year, but the team again curtailed its running early after encountering more cooling problems with the RB10.
Ricciardo said Red Bull was still playing "catch-up" as it battles to get ready for the first race in Australia in two weeks' time.
"Last week we were doing stuff that we would have liked to have done in Jerez and now we're trying to catch up on stuff from last week," he said when asked how far behind Red Bull was. "We're definitely not up to scratch with where we'd like to be in terms of program.
"From the outside, I guess it's just lap times and the amount of laps we're doing, but on the inside we know where we are with performance we're putting in the car and I think we're still confident that we can be up there. But it's hard to say.
"It's clear we probably won't come out to Melbourne and dominate as the team did last year, but it's still very early to say. We're getting there. The morning was definitely better, and we definitely made a step forward in terms of power.
"We just have to worry about ourselves for now and just get the laps in. We'd really like to do some long runs this week and come into Melbourne with some confidence for the race. I think we'd be pleased if we get that done, but there's still a long way to go for us."