He told F1's official website that when the seriousness of the winter problems became clear, Red Bull "intervened".
"Together with Toro Rosso and Renault (we) started a collaboration to move forward," said Marko.
However, he still claims the only "sick" part of the RB10 package is the engine, insisting designer Adrian Newey's 2014 car is better than the dominant Mercedes.
"Yes, (with a better engine) we would be at the top again," said the blunt Austrian.
"But right now with a deficit of around 80 horse power that's simply not possible."
Marko hinted that if it was technically possibly to simply dump Renault and switch to a better engine, Red Bull would do it.
"You are bound to what you have," he said, "as there is no way of saying 'hey, from tomorrow we will use a Mercedes engine' - if they would give it to us - because this car is built around the Renault powertrain," he said.
Marko claimed that Red Bull had to use Renault's Melbourne-spec software in Malaysia because the Sepang version was "not working".
But Renault insists it is now ready to take the next development step for Bahrain.
"The positive is that, unlike Melbourne we don't go to the next race with a substantial job list of rectifications, rather items that will deliver more power and performance in Bahrain," said Remi Taffin.
Marko, however, suggested Red Bull is taking the problem of its straight-line speed deficit into its own hands.
"We are trying everything possible to find more speed on the straights without affecting the corners," he is quoted by German television Sky, "and I have to say that from this point of view we are progressing."
Marko told Bild newspaper: "We are bringing a few new parts from our factory to Bahrain, and also Renault has yet another update for the engine software."