Horner: Red Bull need to find 0.5s to join title fight

What went wrong for Red Bull? (2:11)

Kevin Eason and Jennie Gow ask what went wrong for the biggest disappointment of the opening race, Red Bull. (2:11)

Christian Horner believes Red Bull is 0.5s off the battle between Mercedes and Ferrari but is confident the RB13 has the development potential to catch up.

Red Bull had a disappointing start to the season with home hero Daniel Ricciardo failing to make the start of the Australian Grand Prix due to a gearbox sensor issue and then retiring after 29 laps with a fuel cell problem. Max Verstappen scored 10 points with a drive to fifth behind Ferrari's Kimi Raikkonen, but it was clear from both qualifying and the race that Red Bull has work to do to catch the ultimate pace of Mercedes and race winners Ferrari.

"To be honest I don't think we're that far behind," Horner said. "With Mercedes I think we have about half a second to find. Ferrari have been very impressive here and probably had the quickest car here. We probably had the third quickest car here and we've got to find a good half-second to get into the fight ahead. Max was pushing Kimi [Raikkonen] hard all race but we didn't have the pace of [Sebastian] Vettel or [Lewis] Hamilton.

"I think it is still early days and the regulations are still very immature. We've chosen a different concept and I believe there is really good potential for development with our concept. There are a lot of positives to take out of today at a track we've not been competitive at for the past couple of years. I'm sure we can build on this in the next couple of races."

In recent years, Red Bull has blamed its underpowered Renault engine for its gap to the front, but Horner said the gap this year is spit between power unit and chassis.

"With all these things they come as a package so there is probably an equal share. The problem is the cars seem quite sensitive in dirty air, for Max we didn't see his true potential in clean air. I felt that we had Kimi's pace today but I think we have a half-second to find at this track to be on terms with the cars ahead."

Asked if the team would make a big step ahead of the second round of the season in China, Horner added: "I think it will be incremental at every event. It is the usual suspects and looking at the amount of notes Adrian Newey is taking away I am sure he is going to be pretty busy."