Mercedes' non-executive chairman Niki Lauda said that he was surprised to see Nico Rosberg back on pit lane this month.
Rosberg paid a visit to the team during pre-season testing. He had time to take a selfie with his former engineers, and filmed a short video of the team at work.
"I was surprised, to be honest," Lauda admitted of Rosberg's appearance at the Circuit de Barcelona-Catalunya for a sponsor's event.
"If I wanted to stop, I would stay away for a while to enjoy my child and my wife properly."
But Lauda said that he didn't think Rosberg's appearance meant that the reigning Formula 1 world champion was having second thoughts about his retirement.
"No," he said. "I don't think he'll come back. I think he's comfortable now in his home."
Rosberg shocked the motorsport world by announcing his retirement just five days after winning the 2016 world championship. Mercedes was left scrambling to find a replacement, finally able to lure Valtteri Bottas away from Williams.
Lauda was as surprised as anyone by Rosberg's retirement at the time, and was publicly critical of the driver. However the three-time F1 world champion said he's over that now.
"From the driver's point of view I understand him, but from the point of view of responsibility, it was a surprise.
"In our day, it was really something to become world champion so we always wanted to defend it," he said.
"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 the Austrian broadcaster ORF.