The pair did not see eye-to-eye even before the allegations against Christian Horner - which the 50-year-old was cleared of - came to light ahead of the 2024 season.
In the latest twist in the ongoing saga between the pair, Verstappen accused Horner of being 'childish' for what he says were attempts to block his participation in the above event.
Helmut Marko addresses Horner-Verstappen feud
Marko has now had his say on the matter as tensions have once again been heightened, with the Red Bull chief insisting the focus should be on track and not off it, where the team have enough problems to deal with.
"We have decided to concentrate on the sporting side of things," Marko told Sky Germany.
"We have enough problems there and are sorting them out now.
"The matter is a private matter and banal things like a show run shouldn't really be discussed."
Marko dodged the question when asked whose decision it was not to allow Verstappen to take part in the legends race, stating that his son competing in the main race was what was important.
When quizzed on Max Verstappen's position in the team, the Red Bull chief once again reiterated: "We must and will concentrate fully on the sporting side of things,"
"We have a strong opponent in McLaren. We do have a good lead but this is because the competitors behind us have taken over and there is now only one.