Niki Lauda has criticised Robert Kubica for putting his F1 career at risk by rallying.
The F1 world has united in support for the Polish driver after he suffered horror injuries during a minor event in Italy recently.
Renault is now facing the 2011 season without its star driver, attracting the rebuke from triple world champion Lauda: "It makes no sense for him to put his job and his life at risk like this.
"Was it unreasonable? Of course it was."
The Austrian great said Kubica, 26, should have been banned from contesting rallies.
"He has to ensure that he can do his job, and his job is Formula One. Only he is to blame for what happened to him," added Lauda. "Did he have to be doing this? No!"
In his first interview since the crash, Kubica justified his passion for rallying on the basis that it keeps him sharp amid F1's severe restrictions on track testing.
Answered Lauda: "That's nonsense -- rally driving has nothing to do with Formula One. They are different sports."
Reigning world champion Sebastian Vettel, however, defended Kubica.
"Anything can always happen around the next corner so this has nothing to do with his rallying activity, and it was not his first rally," he told F1's official website.
"I think I speak in the name of all when I say that he is recovering fast and that he will be able to get back into his beloved F1 cockpit very soon," added Vettel.
Meanwhile, Lauda said he thinks Ferrari and Red Bull are currently a step ahead of their rivals for 2011.
"They have both been fast from the start, which is always an indication that it will be a good year for them. McLaren's new car is full of ideas and makes a good impression.
"Mercedes needs to make two steps to get at all those teams, yet it is not possible yet to say if they can do it," he added.