Week 13 is no time to be caught off guard.
Missteps this late in the season can drastically change the direction of a franchise. Coaches can get fired, players no longer trusted as cornerstones, playoff hopes dashed.
Last week, "Upset Alert" went 3-1, with the Tennessee Titans, Arizona Cardinals and Dallas Cowboys all losing to opponents they were favored against. Only the New York Giants took care of business, and they did so convincingly.
Remember the guidelines for Upset Alert: "Underdogs" are determined by Vegas odds; putting a team on Upset Alert is not picking them to lose (it's just putting them on notice); potential Upset Alert teams are based on matchups, trends and team-specific scenarios.
So which teams should be worried in Week 13?
Is Mark Sanchez still the quarterback of the Jets? Does Brandon Moore's rear end still consider him enemy No. 1? Are the Jets coming off of a ridiculously embarrassing loss that made people question if they should be relegated to an arena league somewhere in Eastern Europe?
The answer to all of the above is yes, so that alone puts the Jets on upset alert.
Add in a Cardinals team with an improving offensive line against a Jets team that has trouble rushing the passer, and some shots down the field could shoot down the Jets pretty quickly. If the Jets aren't able to put up points against that Cardinals defense, they'll lose convincingly.
The weather is cooling down in Buffalo, and there's a chance of rain this weekend. You know what that means? It's time for the annual reminder that Ryan Fitzpatrick doesn't really have an NFL-caliber arm.
Meanwhile, the Jaguars are a new team with Chad Henne under center.
No, I'm not going to try and tell you that Henne is the "quarterback of the future" or that he's the answer for everything that ails the team. What he is, however, is world's better than Blaine Gabbert. He's found new life for Justin Blackmon, and passing efficiency can both open up the rushing attack and lessen the pressure on the defense.
Buffalo is going to get its yards on the ground, but if it can't pass and can't stop the Jaguars from doing the same, it's going to be a long afternoon.
It's difficult to put the Giants on upset alert for the second week in a row after they so soundly trounced the Packers on national TV and made me look like a fool for even holding out the chance of a Green Bay victory.
But did you watch the first game against the Redskins?
The last game came down to a last-second glimpse of magic from Eli Manning, and only after Robert Griffin III showcased a little of his own. If the Giants let the Redskins hang around in this one, things could just as easily go the other way.
This one should come down to a ton of passing yards and a ton of points on the board for both teams. If the Giants don't watch out, they could let the Redskins upset them here. That would give the Redskins new life in the NFC East playoff race.
The Giants, like the rest of the teams on this list, are officially on alert.
Michael Schottey is the NFL National Lead Writer for Bleacher Report and a member of the Pro Football Writers of America. Find more of his stuff alongside other great writers at "The Go Route."