It's difficult to consider an NFL game played within the first month of the season is a must-win. For five of the six teams sitting at 0-3, however—the New York Jets are on their bye—Week 4 could bring exactly that.
Only the 1992 San Diego Chargers have made the playoffs after an 0-4 start.
At least one of the aforementioned teams will remain winless along with the Jets. The Cincinnati Bengals and Pittsburgh Steelers face off in the Week 4 finale on Monday night.
Of course, there are some important games that don't involve winless teams, and even two that feature clashes of the undefeated.