They are backups for a reason. All of them.
That is why what the Giants are currently going through is one of the least desirable scenarios a team must confront. When the starting quarterback goes down, there is always a plan. The No. 2 guy moves up on the depth chart, and the No. 3 guy becomes the backup. If the starter is out for a few weeks or more, the hope is the newly promoted starter can keep the offense moving, win as many games as he loses and allow the team to stay in the playoff conversation until his services are no longer required.
When a team knows early in a season that their No. 1 quarterback will not be back until the next season, it is usually akin to juggling raw eggs. Nothing feels comfortable, and there is often an underlying fear that one slight slip-up will lead to a big mess on your hands and on the floor.
Jameis Winston replaced injured Jaxson Dart in Week 2, and now Winston, this week or some time thereafter, could — and probably will — be replaced by J.J. McCarthy.