Fantasy Football Week 15 Start ‘Em, Sit ‘Em: Marcus Mariota vs. Bo Nix

Evaluating who to play in fantasy football in week 15 between Washington Commanders QB Marcus Mariota and Denver Broncos QB Bo Nix.

Nov 30, 2025; Landover, Maryland, USA; Washington Commanders quarterback Marcus Mariota (8) scrambles with the ball against the Denver Broncos in the second quarter of the game at Northwest Stadium. | Peter Casey-Imagn Images

Two QBs who are fairly close to each other in our fantasy football week 15 QB rankings have the possibility of being great plays this week are Washington Commanders QB Marcus Mariota and Denver Broncos QB Bo Nix. Here is a breakdown of who to play between the two this week in fantasy.

Bo Nix

Dec 7, 2025; Paradise, Nevada, USA; Denver Broncos quarterback Bo Nix (10) scrambles against the Las Vegas Raiders during the second half at Allegiant Stadium. | Kirby Lee-Imagn Images

Bo Nix is coming off an ok outing, fantasy football-wise wise against the Las Vegas Raiders in week 14. In the game, he was 31-38 passing for 212 yards and had no passing TDs. He also had three rushes for 15 yards and a TD. This week ranked him as QB15. This adds to a streak of a few underwhelming fantasy football games for Nix. Since week 11, he ranks as QB20 in fantasy. He will look to get back on track on Sunday when he and the Broncos take on the Green Bay Packers.

This season, the Packers are allowing the seventh fewest passing yards per game in the NFL, 185.8. Over the last three games, Green Bay’s play when defending the pass has risen to an even more elite level. They have given up an average of 154 yards per game during this stretch, ranking fourth-fewest amongst teams in the league. The last time Nix played a team in this category of ranking in the top fewest passing yards per game was in week was the Houston Texans in week 9. In the game, Nix went 18-37 passing for 173 yards, with two TD passes and one interception. 

Marcus Mariota

Nov 30, 2025; Landover, Maryland, USA; Washington Commanders quarterback Marcus Mariota (8) reacts after the game against the Denver Broncos at Northwest Stadium. | Peter Casey-Imagn Images

Marcus Mariota did not take the first snaps of last week's, with QB for the Washington Commanders. Jayden Daniels, back as the starter, but he will be the QB1 in week 15 for Washington. Daniels will be out with an Elbow injury he suffered in last Sunday's game. In his last start in week 13 against the Broncos, Mariota played well. He went 28-50 passing for 294 yards and had two passing TDs and one INT. In the game, he also rushed for 55 yards on 10 carries. Mariota, this Sunday, will have a much more favorable matchup than the Broncos when he takes on the New York Giants.

The Giants' passing defense has been bad for most of 2025. In the year, they are allowing the ninth most passing yards per game. Over the last three games, they have allowed two opposing QBs to throw for more than 270 passing yards. All three QBs they faced over this stretch each threw two passing TDs.

Final Verdict

When it comes to who should start and who should sit in week 15 in fantasy football between Mariota and Nix, Mariota should start, and Nix should sit. The main thing that goes into this decision is the matchup and comparing the twos plays of late.

Nix has been in the bottom third of fantasy QBs for the past week, and now he is coming into a matchup against one of the best passing defenses. Mariota is coming off one of his better games this season in his last start and is playing a subpar passing defense on Sunday. Given this, Mariota is clearly the better play this week.