Take him out after the third offensive series.
His counterpart, Stafford, only played two offensive series'. Griffin played four. It's the second pre-season game. Leaving Bob out there was not necessary and (obviously) dangerous given the circumstances.
Griffin is not Matt Stafford. Stafford is a top half of the charts QB in this league. Griffin is not. Griffin needs the work. Everyone wants to point at top tier QBs talking about "would you do it with them" but he's not as good as them. They know pocket presence, they know how to avoid the rush, they know how to read defenses.