Manning is obviously back as the starter. The question is who will be his backup. As of now, Keith Wenning, who signed to the practice squad at the end of last season, is the only other quarterback on the roster. The Giants could bring back Josh Johnson or Ryan Nassib, or add another veteran free agent to serve as Manning's backup. The Giants also could draft a quarterback.
The Giants appear comfortable handing the reins to Perkins. They cut Rashad Jennings early in the offseason and haven't pursued any of the veteran backs on the market.