"I think he just didn’t feel comfortable in the team anymore," Rosberg said on Sky Sports when asked about Ricciardo's Red Bull departure.
"There was this rising star in Max Verstappen who was getting more and more support in the team and he just saw an opportunity to go to another team and be the star there and open up a new chapter and that was his decision at the time.
"I don’t think he would call it a mistake looking back, I’m not sure, but we are all thrilled to see him back.
"He’s such an awesome personality, one of the best wheel-to-wheel racers out there. If I saw him in my rear-view mirrors, that was kind of the last guy I would like to see there at the time – with Max Verstappen – the two of them. So I think it’s great to see him back."