The 20-year-old made 18 appearances last season as Rovers were relegated from the Championship.
Mowbray told BBC Radio Lancashire: "Let's hope he plays a lot of football and becomes a star and helps Forest get to the Premier League.
"That's where I hear the rumours might be, but let's wait and see."
Find all the latest football transfers on our dedicated page.
Blackburn Rovers manager Tony Mowbray is resigned to losing Connor Mahoney and expects the out-of-contract winger to join Nottingham Forest.