Of course there is Eli Manning. He is coming off a career season and a franchise season. He shattered the Giants' passing record for yards in a season, he set. He is also coming off his second Super Bowl MVP. He is in one the most select groups in NFL history, having multiple Super Bowl MVP awards. He is of course going to be the starter and David Carr will be the backup, barring any injuries. David Carr is in his second stint with the Giants, last season he did not appear in any games with the Giants, but him and Eli have similar styles of play, so there is the reason for keeping him.
Now there is only one quarterback left on the active roster, Ryan Perrilloux. He is a second year player with a strong arm. He is likely to get cut and will most likely get signed to the practice squad unless another NFL signs him. Tomorrow is running backs.