It is not time to panic. Even if you lost your season-opening matchup by double-digit points, it is too early to start tearing apart your roster.
This does not apply to those who drafted Le'Veon Bell with the first, second or third pick in the draft. Bell continues his holdout from the Pittsburgh Steelers with the hope of getting a new contract, and while it could end at any time, there are no indications that either side is willing to compromise any time soon.
But while there may not be any reason to panic, it may be worth fine-tuning your roster and grabbing an upgrade.