Rosenberg's 16-year-old wonderkid Sverre Nypan has been watched by scouts from Manchester United, reports in Norway have said.
The midfielder became the youngest player in his club's history last year by making his debut before his 16th birthday, and has begun to establish himself as a first team regular.
He has already made 19 senior appearances in club football and scored three goals at age group levels for Norway.
According to reports in Norwegian outlet TV2, United have been scouting Nypan, who is 'a big fan of both Manchester United and Cristiano Ronaldo.