Berger, a close friend of the Rosberg family, was entrusted last summer with negotiating a new two-year contract for Rosberg with Mercedes, and knows the German driver particularly well.
"It may be that in two or three years he could say to himself 'I do not want to sit at home anymore'," Berger told Austrian broadcaster Servus TV.
"I could imagine him getting bored."
Berger cited the exemples of Michael Schumacher and Kimi Raikkonen as drivers who initially retired from the sport before stepping back in.
Regarding Nico Rosberg, Berger emphasized the world champion's relatively young age, saying that it only made the prospect of a return more plausible.
"The chance is there, especially when he leaves so young and at his peak. No matter what business he gets into, nothing compares with the feeling of driving these cars and standing on the podium as a winner.
"Even if Nico says today that it does not matter to him, I can imagine him getting bored in a few years.
"It will be particularly difficult for Nico because of his age. If you're at the age where you can no longer do what you used to do before, it's different."