Perhaps the most important NFL matchup of Week 15 is not a matchup between division leaders. There aren’t even two teams with winning records.

And yet, in a week full of notable games, there may be no game that could change the playoff picture more than the Indianapolis Colts’ visit to Denver to face the Broncos.

No, it’s not the 10-win Pittsburgh Steelers taking on the 11-win Philadelphia Eagles or the 10-win Buffalo Bills taking on the 12-win Detroit Lions, both matchups on Sunday, that could help to decide the No. 1 seed in the NFC or keep them active, long-range paths to the AFC’s top seed. But these four teams have either already secured a spot in the playoffs or are almost certain of it. Meanwhile, with a month to go before the playoffs begin, both the Colts (6-7) and Broncos (8-5) are still fighting for spots, and they could reshape the wild-card race and, with it, the bottom of the AFC bracket.

Seven teams from each conference advance to the playoffs. The Broncos are in seventh place and the Colts are in eighth place. Denver is one of four 8-5 teams trying to stop the conference’s two 6-7 teams outside of the playoffs: Indianapolis and Miami.

That’s why Colts-Broncos has the feel of a playoff game in December.

With a win, the Colts’ chances of making the playoffs would increase from 25% to 51%, according to NFL.com’s playoff probability tracker. However, in the event of a defeat, this probability would drop to 3%, making it a de facto elimination game. Their ability to potentially make the playoffs would not have been expected in October, when the Colts were 3-3 and had benched their 2023 first-round pick, quarterback Anthony Richardson. Since Richardson was reinstated, Indianapolis is 2-1, with two fourth-quarter comeback wins.

The Broncos, one of four 8-5 teams in the AFC, cannot clinch a playoff spot with a win but have a 91% chance of reaching the postseason, according to the NFL. However, a loss would essentially give them a 50/50 chance.

The Broncos have been one of the NFL’s most surprising stories.

A year after the Broncos moved on from veteran quarterback Russell Wilson to usher in their next QB, Denver and rookie quarterback Bo Nix have won three straight games and five of the last seven, all by double figures. Nix began his NFL career with a tough learning curve, losing his first two games and throwing for just 60 yards in his fourth. But after throwing 12 touchdowns and three interceptions in his last seven games, Nix now trails only Washington Commanders quarterback Jayden Daniels in NFL Rookie of the Year odds, according to Covers.

Since 2000, there have been five seasons in which multiple rookie quarterbacks started in playoff games. With Daniels and Nix, there could be six. But both still have a lot of work to do to get there.

For Nix, that includes winning a matchup on Sunday that will never be confused with the liveliest matchup on the schedule — but may be the most consequential.