Formula 1 legend Niki Lauda has said that he does not think Nico Rosberg will mount a return to Formula 1.

When new world champion Rosberg shocked the world with his post-title retirement announcement, team chairman Lauda was the most openly critical of the move within the Mercedes camp.

However, triple world champion Lauda says that he is now over the shock, having initially declared that a new title winner "would never" have quit "in my day".

"I have to say, in my defence, that in my time at least one driver was killed every year, so we had to have a different approach to the sport," Lauda told Austrian broadcaster ORF.

"In our day, it was really something to become world champion so we always wanted to defend it."

Lauda also said that his criticism of Rosberg was made from the perspective of the Mercedes team.

"We have 1200 employees and it was my responsibility," he said. "From the driver's point of view I understand him, but from the point of view of responsibility, it was a surprise."

Lauda said that he was also surprised when the freshly-retired Rosberg appeared in the Barcelona paddock and pits to watch a day of testing action recently.

"I was surprised, to be honest," Lauda said.

"If I wanted to stop, I would stay away for a while to enjoy my child and my wife properly."

Having said that, Lauda doubts Rosberg might already be thinking about a comeback.

"No," he said. "I don't think he'll come back. I think he's comfortable now in his home."

The new season gets under way in Melbourne next Sunday.