Not sure what you exactly mean with GM, since you have the role of a general manager for your team.(there are also GM like me who moderate the forum, handle signups and catch cheaters)
But i believe you mean someone of the staff:
Doctor: When a player is injured, they affect the length of the injury
Trainer: They impact training speed, and skill decline for old players(every friday)
PR-Manager: They impact your fan survey, which affect your merchandise sells and visitor incomes. But till now we didn't figured out how big the effect is.
Edit: More details here
http://www.buzzerbeater.com/community/rules.aspx?nav=Staf...Last edited by CrazyEye at 3/5/2012 8:07:57 AM