These are the 3 biggest games of Week 15 — for both fantasy football and NFL playoff implications

As we head toward the end of the NFL regular season, massive games for postseason implications intersect with critical matchups for the fantasy football playoffs. In Week 15, we have three such games between teams slated for playoff pushes. Here, I'll break down those three games and the stakes involved for each team using The Athletic's Playoff Simulator, along with a fantasy football note you need to know for both sides.

A blend of both worlds.

Buffalo Bills at New England Patriots

Considering these two teams play in the sme division, I don't think it takes much to see what the stakes are here. The Patriots are already the heavy favorite to win the AFC East after defeating Buffalo at home earlier this season. If they win here, it's over for the Bills' chances to take it back. A win here would also go a long way to increase Drake Maye's odds to win MVP ... or, if the Bills emerge victorious, it might even create a groundswell of support for Josh Allen's case to repeat.

What you need to know for the Bills

We've been in a state of worry and frustration, depending on how invested you are in this offense, over the wide receiver room all season. In Week 14, Gabe Davis led the team in routes run and Brandin Cooks played a big role. That room is what it is and there's no point wishcasting anything else. What does deserve our attention is the play of Dalton Kincaid, who returned to the field last week and continued what looks like a Year 3 leap season.

Dalton Kincaid isn't a full-time player for the Bills, but he's clearly been their most impactful pass-catcher this season.

Here are the top 10 yards per route seasons since 2015 for a TE with 150+ routes. These are the only guys over 2.5. Kincaid is fourth. pic.twitter.com/NNJSR9753M

- Matt Harmon (@MattHarmon_BYB) December 11, 2025

Kincaid needs to rely on efficiency since he's not a full-time player for this team. Good thing he's having one of the most efficient seasons for a tight end in recent history. I think Kincaid is trustworthy as an every-week fantasy starter in the postseason. I sure can't find 10 tight ends who profile better than he does at this stage.

What you need to know for the Patriots

The Patriots are coming off a bye week and I'll be watching for two possible post-bye promotions. In the backfield, TreVeyon Henderson makes for a strong post-bye rookie bump candidate for a running game that needs juice. Given the state of the line, they aren't going to be an effiicnet ground game; might as well lean into being explosive. Henderson clears Rhamondre Stevenson, who has his good qualities, in that regard. Henderson is in a good spot against a Bills run defense that's vulnerable.

In the receiver corps, I'll admit that I've struggled to pick the Stefon Diggs weeks. He's cleared an 80% route participation just twice this year, against the Panthers in Week 4 and the Jets in Week 11. There is no discernible playing time pattern for Diggs. That said, it would make sense for the team to give him an increase in work now that we've arrived at the most critical games, especially this week against his former team that he dunked on for a season-high 146 yards back in Week 5. Given the playing time concerns, you can't rank Diggs too highly but he's at least a high-end fantasy WR3 in this matchup.

Denver Broncos at Green Bay Packers

Since this is our one out-of-conference game, the stakes aren't quite as high. However, both teams need to hold serve to keep pace for division titles.

The Broncos will travel to Green Bay as the heavy favorite to win the division. They've already bested the Chiefs but the Chargers are still lurking. If Denver wins this game and Los Angeles loses, they have a 98% chance of winning the AFC West. On the flip side, the Packers can't afford to look ahead to next week and their rematch with the Bears. If Chicago beats the Browns and Green Bay loses, it's a coin flip for who wins the NFC North and the Week 16 game will carry almost all the weight in deciding it.

What you need to know for the Broncos

RJ Harvey just turned in his best game as a pro and, even if it was in an easier matchup against the Raiders, it was a needed positive datapoint.The Broncos running backs in Weeks 11 and 13 - with Harvey starting - ranked 12th in yards before contact per running back rush attempt (1.41) and 32nd in yards after contact (1.59). They were the only team under 2.0 in this span. Harvey ranked last among qualified rushers in Next Gen Stats rush yards over expected in Weeks 13 and 11. He was having issues leaving yards on the field. That corrected in Week 14, when Denver ranked fifth in yards before (2.15) and 14th in yards after contact (2.85). That is back closer to where it was in the first 10 weeks with Dobbins starting (6th and 12th).

Harvey looked more decisive and hit holes with more authority. The matchup is challenging this week but given his passing game work, goal-line role and improved play in Week 14, I trust Harvey as an RB2 in this game.

What you need to know for the Packers

Since he returned in Week 8, Christian Watson ranks 12th among wide receivers in yards per route run versus man coverage. He's caught four touchdowns against man coverage. This is a critical note as the Packers prepare to play one of the most man-heavy defenses in the NFL.

Watson has been playing the best football of his career so he'll probably draw shadow coverage from Patrick Surtain II. That makes him a risky option in this game but I've found it hard to get him out of my top 20-24 wide receivers based on how well he's played. Be ready to accept some volatility for him this week.

Meanwhile, Jayden Reed caught all three targets against man coverage for 25 yards in his return to action. He's a sleeper candidate against a team that's ceded the fifth-most air yards to slot receivers this season.

Detroit Lions at Los Angeles Rams

The Rams have a 99% chance to make the postseason as it stands today. A win or a loss in this one doesn't move the needle all that much. However, if they lose to Detroit as the 49ers beat the Titans and the Seahawks beat an injury-ravaged Colts team that is potentially starting a 44-year-old quarterback, their chances to win the NFC West drop below 40%.

The Lions don't have much of a shot to win their division at this stage but are alive in the NFC Wild Card race. Since this is a conference game, they need a win here. Their playoff chances will swing between 60% and 30% based on the result.

What you need to know for the Lions

In the previous nine weeks of the season, Jameson Williams was one of the most disappointing players in the NFL. He was barely involved in the Lions offense. Since Week 10, he's been incredibly productive on a per-route basis, despite taking a zero in a matchup.

Jameson Williams is a fun case because you get to choose your own narrative for his turnaround/better target "earning" the last month.

Weeks 1 to 9 per route data (left) vs. Weeks 10 to 14 per route data (right).

- Did Dan Campbell taking over the play-calling save Jamo's... pic.twitter.com/b0p9hM9tGb

- Matt Harmon (@MattHarmon_BYB) December 11, 2025

Whether it's because Dan Campbell took over play-calling from John Morton, or simply because Sam LaPorta went on IR, Williams has begun to get the volume many hoped to see before the season. In this matchup against a Rams defense that, if you can beat their pressure packages, is vulnerable on the back-end, I'd be chasing Williams' ceiling outcomes.

What you need to know for the Rams

In previous years, Sean McVay has typically just entrusted his backfield to one man at a time. That has been even more true in the Kyren Williams era. And yet, as we head toward the end of the season, Blake Corum appears to have officially made this into a committee backfield.

While Williams still holds the clear lead (61% to 33%) in snap rate, Corum owns a 36% share of the backfield touches and has amassed 236 yards from scrimmage since Week 12. Even better, he's gotten way more work inside the two-yard line, with a 50% touch share to 25% for Williams.

Williams remains a fantasy starter because this offense is so good that both backs can eat. He's also the clear-cut passing-down option. However, Corum is now on the flex radar, even in a tough matchup like this one. Bare minimum, Corum needs to be on fantasy rosters just in case there's an injury to Williams.