Mercedes boss Toto Wolff says that if Red Bull's two teams pull out of Formula 1, other top teams might be asked to run third cars.
The process of introducing third cars could in theory be kick-started if the 2016 grid drops below 20 cars.
Mateschitz's threat to quit Formula 1 has been taken seriously up and down the paddock.
"If a team would leave, and we have had the discussion around Lotus a while ago, third cars are a solution to fill up the grid," Wolff said when asked by Motorsport.com.
"For me personally it's a pretty exciting idea.
"I'd rather have Red Bull in the sport and third cars, and a grid of 27 or 28 cars, and some exciting young drivers in those third cars. But this is definitely one of the fall-back positions."
Wolff said, however, that the situation had not yet been discussed in connection with Red Bull: "I think priority number one is to keep them in the sport."
Wolff admitted that it would be a huge blow to F1 if Red Bull went through with its threat to quit.
"You can't close your eyes to the fact that this is a platform, and it needs players, and it needs a competitive environment, and it needs competitive teams, and that was part of our consideration.
"But then it is also an environment where you need to look at yourself and the team's performance with a priority.
"So it comes to the decision of whether you'd rather go with the platform, or with the good sport, or you'd rather go with your team's perspective, and it's clear from our point of view that you need to prioritise your own competitiveness.
"This is absolutely clear, and we are very conscious about it. So I hope whatever decision they take they are going to decide in favour of F1, and grow F1, and take it from the competitive side."