Niki Lauda believes Fernando Alonso would not be a good mix for Red Bull while Ferrari should try to sign Kimi Raikkonen.
Red Bull are in the hunt for a driver to replace Mark Webber next season with Raikkonen and Daniel Ricciardo leading the running.
The duo, though, became a trio during the summer break when reports linked a frustrated Alonso to Webber's vacant seat.
At the same time other rumours arose suggesting that Raikkonen could in fact be returning to Ferrari next season as Alonso's team-mate.
Asked who he reckons Red Bull should sign, Lauda told Auto Motor und Sport: "Not Alonso for sure. That would only bring trouble to the team.
"With probably four World Championship titles with Vettel, Red Bull has the luxury of weighing Raikkonen and Ricciardo in peace.
"The one is the better short-term solution, the other long.
"They can take a risk in their driver choice. But not Ferrari."
In fact Lauda reckons Ferrari should look at getting two number one drivers as they are now a team under pressure.
"If Raikkonen doesn't go to Red Bull, then Ferrari should try to get him on board in order to have a counterweight to Alonso.
"After six years without a title, Ferrari is under great pressure."