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There are some huge games in NFL Week 12 that will have a significant impact on the playoff chase, and we’re bound to see a few big upsets along the way.

The two teams atop the overall standings are both in danger of being upset in Week 12. We’re also highlighting other playoff contenders that could see their postseason dreams take a big hit this Sunday.

The following six teams, favored to win in NFL Week 12, are being put on upset alert.

Denver Broncos vs. Buffalo Bills (-4)

It’s easy to see why the Broncos are road dogs this Sunday. Denver will have significant challenges with Brandon Allen under center, going against a Buffalo’s strong defense. However, despite his lack of experience, the former sixth-round pick out of Arkansas has given Denver’s offense a boost with big plays downfield, and he’s certainly done a better job than Joe Flacco did before him.

What really makes us believe the Broncos could pull off an upset in Buffalo is that Denver’s defense is in the top-10 against the run and No. 4 overall. Aside from the second-half collapse last Sunday in Minneapolis, this defense has been very strong since fixing some early issues. If second-year Bills quarterback Josh Allen can be pressured into a mistake or two, the upset is there for the taking.

New York Giants vs. Chicago Bears (-6)

Yes, the Giants are in the midst of a six-game losing streak. Yes, the Bears still have a ferocious defense, and yes, Daniel Jones tends to fumble.

None of that gives us any confidence the Bears will win, though.

Thanks to a distinct lack of development from third-year quarterback Mitchell Trubisky, Chicago ranks third-worst in total offense and fifth-worst in scoring. Despite playing very well recently against the Detroit Lions, Trubisky has been brutally inefficient. He is also coming off a hip injury, and Chicago’s offense scares nobody.

Tampa Bay Buccaneers vs. Atlanta Falcons (-4)

A team that couldn’t buy a win until a few weeks ago, Atlanta is suddenly formidable, winning its last two games thanks to a dominant defensive effort. On Sunday, the Falcons are hosting NFC South rival Tampa Bay, which has been beating itself with mistakes almost weekly this season.

Jameis Winston leads the NFL with 18 interceptions and is coming off a brutal Week 11 effort against the New Orleans Saints. Yet when he’s on his game, he’s difficult to beat.

Should Winston wake up on the right side of the bed Sunday and have one of his “good” games, the Bucs have the offensive firepower to light up the scoreboard and beat their rival.

Jacksonville Jaguars vs. Tennessee Titans (-3.5)

Both of these AFC South teams are still technically alive for the postseason. Neither Jacksonville (4-6) and Tennessee (5-5) can afford another loss, though, meaning the stakes for Sunday’s game are extremely high.

Nick Foles did a pretty solid job in his first game back from a collarbone injury last Sunday, and the Jags have an excellent balance on offense with Leonard Fournette pounding the rock. Jacksonville’s defense must get back on track and pressure Ryan Tannehill after two poor outings against Houston and Indianapolis. If it happens, we’d expect to see a heavy dose of the run game offensively in what’s sure to be a hard-hitting game on Sunday afternoon.

Dallas Cowboys vs. New England Patriots (-6.5)

Dallas has a couple of things going well for it heading into this Sunday afternoon game at Gillette Stadium in Foxborough.

First of all, quarterback Dak Prescott is having an MVP-caliber season and has excelled in recent games that saw Ezekiel Elliott bottled up on the ground. In the past two games, Prescott passed for 841 yards, six touchdowns and one interception. Sure, the Patriots feature the best pass defense in the NFL, and it will certainly make life difficult on Prescott and Co., but this young quarterback has been white-hot lately and could still triumph.

Secondly, Tom Brady is really having a hard time of late. He’s visibly upset with how little success his offense has had. It also seems like the lack of talent may finally be too much for him to overcome against the NFL’s best teams, especially now that an elbow injury is hampering him.

Green Bay Packers vs. San Francisco 49ers (-3)

One of the most pleasant surprises of this NFL season has been the amazing turnaround engineered by John Lynch and Kyle Shanahan. The San Francisco 49ers have lost only one game and control the NFC heading into Week 12. But now we’re about to find out just how much of a championship contender the 49ers really are.

Starting with this game against the Packers, the 49ers face three teams in a row with a .800-plus winning percentage — the most difficult three-game stretch any team has encountered this late in the season.

Green Bay has the players to wreak havoc on San Francisco, too. With a run game that can relentlessly make big plays and a defense that gets after the quarterback, the Packers will be tough to beat. Especially if the dominant 49ers defense keeps regressing like we’ve seen the past few weeks.