Fantasy football start 'em, sit 'em: Can 49ers QB Brock Purdy bounce back in Week 17?

It's the final week of the 2023 fantasy football season, and one lineup decision could determine whether your team takes home the championship. Congratulations on making it this far — now here's what to do about a few players who you may be on the fence about starting in Week 17.

Quarterbacks

Start: Brock Purdy, San Francisco 49ers

49ers at Commanders / 1 p.m. ET Sunday

The 2022 Mr. Irrelevant cost himself the MVP Award with last week's four-interception outing against the Ravens but is well-positioned to redeem himself with a strong performance in Washington. The Commanders' defense stands in stark contrast to Baltimore's unit, as it allows the most fantasy points per game to quarterbacks this season (20.6) and has surrendered the most passing touchdowns (33). And now that Commanders QB Sam Howell has been benched for Jacoby Brissett, this game could turn into a shootout if the 49ers defense has another dreadful showing, which would greatly benefit Purdy’s fantasy outlook.

Other starts: Dak Prescott, Dallas Cowboys; C.J. Stroud, Houston Texans 

Sit: Geno Smith, Seattle Seahawks 

Steelers at Seahawks / 4:05 p.m. ET Sunday

While Smith played well last week in his return from a groin injury, his production is often determined by the play of his wide receivers, and the Steelers' secondary will present a formidable challenge. Pittsburgh has allowed the fifth-fewest fantasy points per game to wide receivers over the past month (24.1), with only two players at the position scoring touchdowns in that span. Additionally, the Steelers have racked up the fourth-most interceptions this season (16) and picked off three passes from Bengals QB Jake Browning just last week. 

Other sits: Jared Goff, Detroit Lions; Tua Tagovailoa, Miami Dolphins

Running backs

Start: Devin Singletary, Houston Texans

Titans at Texans / 1 p.m. ET Sunday

Even with last week's 9.3 PPR point showing, Singletary has proven to be viable with an extensive workload, and while his upcoming matchup doesn't seem favorable, it's actually much more intriguing than it appears. On the season, the Titans allow the 12th-fewest rushing yards per game, but they'll once again be without DT Jeffery Simmons, which drastically hinders their ability to stop the run. As pointed out by Underdog Fantasy's Hayden Winks, the Titans' defense ranks as the sixth-worst unit in rushing success rate allowed without Simmons. 

Other starts: Ty Chandler, Minnesota Vikings; Zamir White, Las Vegas Raiders

Sit: Raheem Mostert, Miami Dolphins

Dolphins at Ravens / 1 p.m. ET Sunday

Despite being one of the most surprising fantasy superstars this season, Mostert — who is tied for the NFL lead in total touchdowns (21) — could derail your championship bid. The 31-year-old logged a season-low 19 snaps in last week's win over Dallas due to ankle and knee issues and took part in only two third-quarter plays before HC Mike McDaniel benched him to manage the injuries. Mostert would be a risky start even if he were healthy, considering Baltimore allows the seventh-fewest fantasy points per game to running backs (18.1), though he'll be even less productive if he's on a pitch count. 

Other sits: James Conner, Arizona Cardinals; David Montgomery, Detroit Lions

Wide Receivers

Start: Cooper Kupp, Los Angeles Rams

Rams at Giants / 1 p.m. ET Sunday

It's been a disappointing season for most Kupp managers, mainly due to his preseason ankle injury and the emergence of rookie sensation Puka Nacua. However, Kupp ranks seventh among wide receivers in targets (38) over the last four games, so if his 10.9 PPR point performance last week didn't end your season, start him with confidence against the Giants. New York allows the sixth-most fantasy points per game to wideouts this season (38.1). 

Other starts: Stefon Diggs, Buffalo Bills; Michael Pittman Jr., Indianapolis Colts

Sit: Drake London, Atlanta Falcons

Falcons at Bears / 1 p.m. ET Sunday

The upgrade to Taylor Heinicke at quarterback didn't pay off for London, as he posted just 6.9 PPR points in last week's 29-10 win over Indianapolis. Although his uncertain rapport with Heinicke could mean London has more of an impact this week, the odds are against him. London averages 7.37 PPR points on the road compared to 15 PPR points at home this season and will face a Bears defense that has been the 10th-most difficult matchup for wide receivers over the last four games. 

Other sits: Tee Higgins, Cincinnati Bengals; Adam Thielen, Carolina Panthers

Tight Ends

Start: Trey McBride, Arizona Cardinals

Cardinals at Eagles / 1 p.m. ET Sunday

After posting at least 20 PPR points in his previous two games, McBride cooled off last week, hauling in six of eight targets for 31 yards. Still, the second-year tight end has too much value to leave on the bench, given that his 15.8 PPR points per game since Week 8 would place him as the WR13 overall in that span. Count on McBride to re-establish himself as QB Kyler Murray's top target against an Eagles defense that gives up the 13th-most fantasy points per game to tight ends (12.5). 

Other starts: Sam LaPorta, Detroit Lions; Darren Waller, New York Giants

Sit: Tucker Kraft, Green Bay Packers

Packers at Vikings / 8:20 p.m. ET Sunday

Those who lost Minnesota's T.J. Hockenson (knee) might be inclined to take a flier on Kraft if he's still on the waiver wire, seeing as the rookie ranks as the TE8 overall since Week 14. Even so, with Packers WR Jayden Reed back in the lineup after missing last week's contest with chest and toe injuries, Kraft's modest target share is likely to grow even smaller. It's also worth noting that Minnesota has conceded the 11th-fewest fantasy points to the tight end position this season (157.1) as well as the ninth-fewest red zone fantasy points on a per-game basis (0.5). 

Other sits: Dalton Kincaid, Buffalo Bills; Chigoziem Okonkwo, Tennessee Titans