"Mercedes and Ferrari don't just try to get our top employees; they are trying at every level (of the team)," said Marko.
In reality, Red Bull and Ferrari have a more immediate problem even than a tug-of-war over F1's most sought-after and highly paid engineer.
At the Circuit de Catalunya, a layout expected to play into the hands of Mercedes' rivals, Lewis Hamilton was a clear second faster than any other qualifying pretender.
Not only that, world champion Sebastian Vettel is having one of the worst grand prix weekends of his formerly glittering F1 career.
Despite having switched his RB10 chassis before the Barcelona weekend, the German has struggled simply to get his new Red Bull to run in Spain.
"It's getting a bit boring," Vettel said on Saturday. "We've had all sorts of problems this year."
Boring perhaps, but the quadruple title winner is at least retaining his sense of humour.
Asked if his 2014 travails are a good test of his mettle, Vettel replied: "Well, I haven't been tested on the track much so far!
"If you compare my salary with the number of laps I've done, then I am the best paid driver," he smirked to Germany's Auto Motor und Sport.
Vettel sat out most of Friday and also broke down in qualifying, so he added: "I'd say I'm well rested for the race."
Gerhard Berger, once Vettel's boss at Toro Rosso, also thinks motivational issues may be creeping into the 26-year-old's struggles.
"Firstly he knows that he has no chance with this Renault engine," said the former McLaren and Ferrari driver.
"And certainly after always being at the front for four years and giving everything, in this situation you could find that your batteries are getting low," added Berger.
But Red Bull's Marko thinks the real problem is simply Mercedes' increasing dominance.
"We are one second from them. In the race we won't see Mercedes," he said.
"We are making small steps forward, but so are they. We need a quantum leap, otherwise for us the year is over," added Marko.
It is believed Red Bull wants to introduce substantial fuel and engine modifications in time for its home race in Austria next month, but this might require a relaxation of the engine 'freeze' rules.
"The rules are clear, and we stick to them," Mercedes F1 chairman Niki Lauda, apparently ruling out cooperation to help struggling Renault, insisted.
So for now, Marko admitted he is hoping Lewis Hamilton and Nico Rosberg's lonely battle at the front comes to blows.
Lauda, meanwhile, is taking delight in Mercedes' current situation.
"I was really concerned that our lead would be smaller on an aerodynamic track like Barcelona," he said. "But we are even further ahead of Red Bull than before."