When a team is playing without its quarterback, all data goes out the window. Their play-calling tendencies change, their efficiency shifts drastically, and the team may even operate at a slower pace to mask its vulnerabilities.
When the quarterback comes back, then, it means that we essentially have to reset all expectations for the entire team and start from square one. That's what we have to do with the New York Jets this weekend.
Sure, Sam Darnold might not be at his optimal conditioning after missing a month due to mono, and that matters.