Vettel has won the past three Formula One championships with the pair teaming up to guide Red Bull to the past three Constructors titles too.
However, Webber has regularly made his displeasure at his team’s preference to the German public.
Nonetheless, Marko told Sport Bild that nothing would change ahead of the 2013 season, with the Australian signing a new one-year deal with Red Bull.
“Mark knows what we expect of him,” Marko said.
“For four years, Vettel and Webber have driven together in our team. Sebastian was runner-up once and champion three times.
“The statistic speaks for itself. There is no reason to think the balance of power will change.”