Although the energy drink owned team will introduce a ‘B’ spec car in Barcelona this weekend, engine partner Renault has delayed a performance upgrade.
Still, Horner is upbeat.
“The new regulations are still very immature and we will definitely get stronger,” he is quoted by Speed Week.
“Obviously Ferrari and Mercedes have been better than us so far, but we’ve tried to keep the damage within limits. We still have our chances to catch up.”
There are suggestions Red Bull’s situation has left driver Daniel Ricciardo deeply frustrated, and potentially open to a switch to Ferrari for 2018.
Horner said: “I cannot see a difference between the Ricciardo now and the Daniel I know from past years. Of course he wants to be competitive but he isn’t moaning. The 2015 season was much more frustrating for him.
“I am convinced that we have the most exciting driver pairing in the sport,” he added.
And although Red Bull is not yet vying for wins, Horner said he is happy that the formerly-dominant Mercedes team finally has a rival in the form of Ferrari.
“It’s great for the sport. Formula one has a new winner in Valtteri Bottas, we’ve had four races where beforehand no one could have predicted with certainty who would win. Three winners in four grands prix — may it continue,” he said.