How often is Brad Greenquist in this film ?

The man you're asking about it much younger in this movie than the picture on his profile here, but if he's who I think he is, the role is not very big at all.

----------
"If I've never seen it before, it's a new release to me."

Brad's a background character here, as a prosecutor. He doesn't have a whole lot of screen time, and if you watch this film just for him, you might be disappointed. Regardless, this is a very strong film with an excellent cast, and seeing Lemmon and Scott duke it out makes any film worthwhile.