Red Bull has the potential to challenge Mercedes and Ferrari this season despite a slow start to pre-season testing, according to Daniel Ricciardo.

The Milton Keynes squad is yet to threaten the top of the times after three days of testing in Barcelona, which have been dominated by Mercedes and Ferrari.

After an eventful opening day hampered by two technical glitches, the RB13 has run strongly in the hands of Ricciardo and team-mate Max Verstappen, albeit more than a second shy of the front runners.

The 27-year-old however remains confident Red Bull will pose a threat to Mercedes and Ferrari after revealing the squad is yet to focus on extracting the ultimate pace from its machine.

“I think for now we haven’t really got too involved in the performance runs.” said Ricciardo, who was third fastest on the third day of the test.

“We’re trying to get some laps, some consistent laps, for reliability as well, to make sure nothing’s getting hot or there’s no problems.

“The lap times, for now it’s still not too representative but I think we can expect Mercedes and Ferrari to be at the front. But I think we can be very close as well.”

Ricciardo has also admitted that there is still more to come from Renault’s new and improved power unit.

“For now, this first test, we’re pretty happy,” he said of the engine.

“We know there’s a bit more to come, but hopefully next week we can start to push it a bit more and I think by the end of next week everyone will be seeing what they’ve got.

“I’m confident we can be again a bit closer than we were last year, and we’ll see from there. Today’s been globally positive.”

The final day of the opening pre-season test will begin later today.