Red Bull's hopes of taking the fight to Mercedes when Formula 1 returns in Austria this weekend have been further boosted by an upgraded powerunit from engine partner Honda.
As the Australian Grand Prix was called off before cars left the pitlane, all teams are free to bring new car and engine packages to the Red Bull Ring.
Speaking in a team preview, Red Bull boss Christian Horner said that Honda would be bringing what was its original second version of the powerunit to the Red Bull Ring.
"We have an engine upgrade, as we essentially introduce what would have been engine number two, which becomes our first engine," he said.
"So in all aspects of the car, there has been an awful lot of work go into [it], and it's been a race against the clock to get those updates onto the car since reopening the factory at the beginning of June."
Red Bull revealed some changes to its car during its Silverstone filming day last week, with Horner says the team is introducing parts that had been planned for the early phase of the campaign.
"We don't really know where we stand going into Austria and of course the car would have been developed," he explained.
"There would have been updates at the first European races at Zandvoort and Barcelona, and there would have been further updates for Montreal.
"So of course all the updates that were in the pipeline prior to the shutdown, plus whatever we've learned subsequent to the shutdown, have been implemented to the car.
"There are subtle revisions all over the car as part of that update process which I'm sure the other front running teams have also done."
Horner also praised the ever-strengthening relationship with Honda, which he hopes can help it fight for the world championship this year.
Max Verstappen won three Grands Prix last year, following Honda's first victory as an engine manufacturer since 2006 at the Red Bull Ring with further wins at Hockenheim and Interlagos.
"As we head into our second year of our Honda relationship it feels much more integrated within the team," he said.
"We enjoyed a great debut season with Honda winning three races, and of course now we're looking to build on that.
"They're ambitious, they share the same ambitions that we do, they've been working tremendously hard during the off-season and of course come into this year with higher expectations.
"It's a key part of the car and a key partner for us as we move forward and look to mount a challenge for championships in the future."