But not his own. Regarded as energy drink magnate Dietrich Mateschitz's right hand man on F1 matters, the coarse and outspoken Austrian Marko said his pact with his billionaire boss was "settled with a handshake".
So would he commit right now to at least another five years at Red Bull?
"Yes, something like that," Marko, a doctor of law and former driver, told Kleine Zeitung.
But as for members of the ultra-successful Milton Keynes based team who have signed up in black ink, Marko admitted that he looks "every six months at all the major contracts" and attempts to renew "those that should be extended".
Undoubtedly, he is referring to key figures like Sebastian Vettel and Adrian Newey, but the latest speculation had been about Briton Horner, Red Bull's 39-year-old British team principal who had been linked to Ferrari.
Marko said only: "There are not many (in F1) who do not try to poach staff from Red Bull."