Mercedes non-executive chairman Niki Lauda says "half of the grid" have contacted the constructors' champions over replacing the now-retired Nico Rosberg.
Rosberg stunned the Formula One world by announcing his exit from the sport on Friday, less than a week on from winning his maiden drivers' world title.
Some of F1's stellar names - including Sebastian Vettel, Fernando Alonso and Max Verstappen - have all been linked with the vacant seat to drive alongside Lewis Hamilton, while Mercedes junior driver Pascal Wehrlein has also been touted as a potential successor, after spending last season with Manor.
Lauda hinted that Mercedes would be cautious in backing a relative rookie like Wehrlein as they aim to continue their dominance of the sport amid 2017's sweeping regulation changes.
"Practically half of the grid have offered their services," Lauda told Gazzetta dello Sport.
"We have lost a champion - the best driver of 2016. It won't be easy to replace him because all the drivers of a certain standard have contracts with other teams.
"Taking a young driver is a risk, we don't know if he will be strong."
A three-time F1 world champion himself, Lauda said he found Rosberg's decision to retire after winning his first crown curious.
"A few hours before the public announcement, he told us by phone," the Austrian said. "I took the news badly, I didn't expect it, nobody in Mercedes thought that he had had enough.
"At first I didn't believe it. 'Nico, what you told us, are you kidding? Is it a joke?' But he said it was all true. Quite incredible.
"When I won the first title I immediately thought about how I would win a second. That's not the case with Nico. His decision has left us disorientated and unprepared, and all those who contributed to Nico winning the world title took it very badly."