But on Tuesday, the Austrian was quoted by SID news agency: "We will express ourselves when the time comes, and that will definitely not be at Spa."
24 hours ago, Kimi Raikkonen's manager Steve Robertson said talks with Red Bull had ended. Reports suggested the 2007 world champion is now more likely to return to Ferrari in 2014.
Marko did not want to comment.
"What we will do will be the best for the team, in the medium term," said team owner Dietrich Mateschitz's right-hand man.