The San Francisco 49ers take on the Los Angeles Rams on Thursday night, kicking off week five of the NFL season. Here is an evaluation on who to start and who to sit in fantasy football between the starting quarterbacks of the contest, Matthew Stafford and Brock Purdy.
Sep 28, 2025; Santa Clara, California, USA; San Francisco 49ers quarterback Brock Purdy (13) passes the ball during the first half against the Jacksonville Jaguars at Levi’s Stadium. / Kyle Terada-Imagn Images
San Francisco 49ers QB, Brock Purdy, was back in action in week four after missing weeks two and three with a turf toe-related injury. He had an up and down day in what ended up being a 26-21 loss against the Jacksonville Jaguars. He went 22-38 for 309 yards and had two touchdowns and two interceptions.
As of now, Purdy’s availability for Thursday night is up in the air. He is currently listed as questionable for the Thursday night contest and has been a non-participant in practice both Monday and Tuesday. The injury bug has bitten Purdy and some other notable offensive players on the 49ers, and with them facing a tough secondary in the Los Angeles Rams, starting Purdy in fantasy feels like a questionable play.
The Rams so far in the 2025 season have allowed the ninth fewest passing yards per game.
Along with Purdy being out, George Kittle is still out with an injury, and WR1 and WR2–Ricky Pearsall and Jauan Jennings–both did not practice on Monday or Tuesday. Jennings has been dealing with injuries all year and appeared to get even more banged up against the Jaguars. Pearsall also got hurt in the Jacksonville game, aggravating his knee after hitting the gridiron hard in the third quarter, while trying to make a play on a pass by Purdy.
|Sep 28, 2025; Inglewood, California, USA; Los Angeles Rams quarterback Matthew Stafford (9) throws against the Indianapolis Colts during the second half at SoFi Stadium. / Gary A. Vasquez-Imagn Images
At 37 years old Matthew Stafford is putting together another solid season. Through four weeks, he has thrown for 1,114 yards, eight touchdowns, and two interceptions. He is coming off his best game of his 2025 campaign against the Indianapolis Colts, where he threw for 375 yards, three touchdowns, and no interceptions. This performance by Stafford produced the second most fantasy points out of any QB in week four. His week five opponent, the San Francisco 49ers, will be a tough opponent for Stafford to have a similar game.
The San Francisco 49ers have allowed the sixth-fewest passing yards per game so far this season. On top of that, Stafford has recently played below par against the 49ers. In his last four games, he has a combined three touchdowns and two interceptions. In his career against them, he has a 3-8 record.
Between Stafford and Purdy, Stafford should be a start in fantasy football, while Purdy is a sit. There is too much uncertainty on how healthy Purdy is, and his pass-catching weapons being banged up against a good secondary is all the more reason to sit him out. Stafford, having an elite healthy receiving corps in Davante Adams and Puka Nacua, is a big separator in this debate, but Stafford is still not an ideal start option. San Francisco also has a top secondary, and as shown, Stafford has not been great as of late against them. So, surveying and looking for another QB option, with a more favorable matchup, is probably the way to go.
