How to add author context (rel=author) when you have multiple authors in one site?

Hi there,
I would like to use Google rel=author meta tag, but I do have several authors writing in one site.
How should I manage in that case?
I was planning to use meta tag module, but the only way it seems to modify all urls in order to affect different url with different meta tags.
ie: /authorname/title that way, with different urls I could create different meta tags.

Could that be a normal procedure? Or there´s another way to add the author´s context?
Thanks!