It's still up in the air whether Vince Gilligan's Bob Odenkirk-centric Breaking Bad spinoff Better Call Saul is a prequel, sequel, or takes place during the time frame of its predecessor, but Gilligan tells EW that he wants Jonathan Banks to potentially reprise his role of Mike Ehrmantraut on the new show.
When asked if he wants any Breaking Bad character to pop up or have an extended role on Saul, Gilligan replied:
The character that springs to mind would be Mike. That would be a great deal of fun. I would say the sky’s the limit, at least theoretically speaking. Realistically speaking, we’ve got a whole lot [...]