In a hypothetical match between Nottingham Forest and Manchester United, it is likely that Manchester United would be considered the favorite to win. They are a historically successful and highly competitive team in the English Premier League, with a strong roster of skilled players.

Nottingham Forest, on the other hand, currently competes in the English Championship and has not been in the Premier League for several years. While they have a rich history and passionate fanbase, they may face a tough challenge against a powerhouse team like Manchester United.

That being said, anything can happen in football and upsets are always a possibility. In a one-off match, Nottingham Forest could potentially defeat Manchester United if they put in a strong performance and capitalize on any mistakes made by their opponents.