Toto Wolff has repeated his warning that there is no guarantee Pascal Wehrlein will make his F1 debut with Manor next year.
Before the newly 21-year-old German wrapped up the DTM championship at the weekend, Mercedes' Wolff had warned that Manor's new Mercedes engine deal was no guarantee of a route into F1 for Wehrlein.
"With a Mercedes engine and Williams technology as well, Manor now has a valuable cockpit to sell," Wolff had said.
Indeed, Will Stevens and Alexander Rossi - and their respective backers - are both pushing hard to keep their places at Manor beyond 2015.
So even with his firm Mercedes link and now a DTM title in his pocket, "It is far from certain that Pascal will go to Manor", Wolff told Speed Week.
"If they (Manor) ask too much, it will not work out," the Mercedes chief added. Wehrlein admitted last week that "it may well be that we decide to go for another year of DTM" in 2016.
Wolff added: "But if third cars come (in F1), Pascal has another chance."
However, Wehrlein's achievement at Hockenheim at the weekend is just the latest feather in the cap for Mercedes, who are also on course to win the drivers' title in F1.
"The constructors' championship in formula one, probably also the drivers' as well and the DTM drivers' title in one season has never been done before," Wolff beamed.
Bahrain International Circuit - Winter testing