Daniel Ricciardo is confident his car’s new power plant won’t fail after his troubled preparation for the Australian Grand Prix.

The Australian missed a practice session in Melbourne on Friday as his Red Bull Racing mechanics replaced the unit.

The setback came as Mercedes set the pace in the two practice sessions at Albert Park.

Ricciardo says his car’s problems will be fixed in time for another practice session on Saturday from 2pm AEDT, ahead of qualifying from 5pm AEDT.

“It’s a small setback but I think we can still get our stuff together tomorrow morning and still have a strong qualifying,” Ricciardo told reporters on Friday.

“There’s no concerns about tomorrow. It was a job not worth rushing … it was just do the work properly and make sure we have got a race car that is capable of doing more laps tomorrow.”

Ricciardo was 10th fastest in the opening session and Mercedes duo Nico Rosberg and Lewis Hamilton were fastest on Friday, clocking times almost one second quicker than the next best, Ferrari’s Sebastian Vettel and Kimi Raikkonen next best.

“I am happy with today and with Lewis it’s always nip and tuck, quite close, so I have to nail it tomorrow,” Rosberg told reporters on Friday.

“For now I haven’t found the car balance 100 per cent, there’s too much oversteer for now, that makes it risky to drive. We have to work on it.”