Red Bull team principal Christian Horner has joked the team has been "going to church every week to pray" for a swift update from Formula One engine supplier Renault.
The quadruple world champions were tipped to challenge Mercedes for the F1 title this year following an overhaul to the sport's aerodynamic regulations for 2017, but it is Ferrari who has emerged as Mercedes' closest rivals, with the two teams battling it out for race wins during the early stages of the season.
Red Bull had been as much as 1.8s off the pace in Australia but has made significant progress since, closing the deficit to 0.