The Australian finished second-quickest in second practice behind the Ferrari of Sebastian Vettel, as Mercedes drivers Lewis Hamilton and Valtteri Bottas struggled for pace.

Ricciardo joined Sebastian Vettel in admitting that Mercedes' pace was "weird", but he is expecting the German squad, and his own Red Bull team, to be in the fight on Saturday.

"It's weird. Obviously this morning they looked strong, particularly Lewis, and then this afternoon it kinda looked like they put more fuel in the car or something," Ricciardo said.

"We'll see. If that's genuine then it reminds me a little bit of Singapore '15. If that's the case, beauty, but I expect them to be... If we all get it together on Saturday, it should be a three-way fight.

"There's a few little things that I definitely want to work on, but generally we are in that window where we need to be and not a second off or anything, so that's promising," he added.

Teammate Max Verstappen, third in the morning session but only sixth in the afternoon, insisted Red Bull still needs to improve despite what he labelled as a positive day.

The Dutchman also blamed a "messy" second practice for his position in the timesheets.

"We can be quite pleased with the performance we had so far," he said. "Just in the second practice it was a bit messy, going out on the second set and then the red flag came out on my lap.

"I think in general, if you take all the sectors together, it's alright. You don't need to be the quickest on Thursday, that's what I learned. It was positive but we still need to improve."

Additional reporting by Erwin Jaeggi