Dr Helmut Marko says he will be making no further comment about Sergio Perez's cultural origins in Singapore this weekend.
After Monza, Red Bull's notorious team advisor caused a major stir by inaccurately referring to Mexican Perez as "South American" and declaring that it explains his lack of focus compared to Max Verstappen and Sebastian Vettel.
The 80-year-old Austrian subsequent apologised following a backlash, including from organisers of the Mexican GP, and says he is now drawing a line under the affair.
"If there are any questions, I won't answer them," he told f1-insider.com about the forthcoming Singapore GP.
"I will only talk about sporting matters."
On the sporting front at least, things are going very well for Red Bull, having so far won every grand prix this season - including Max Verstappen's record-breaking 10-race winning streak and counting.
Marko, however, says he is nervous about Singapore.
"A lot can always happen there," he said. "Max has never won in Singapore either."
Not just that, but race organisers have also made significant changes to the barrier-lined street circuit for 2023.
"Corners 16 to 19 have been eliminated," Marko confirms. "This makes the course faster and more unpredictable for us.
"But what worries me most is Ferrari. They were already very strong in Monza. So if we get through Singapore on a positive note, I can sleep a little more soundly."
