Fantasy Football Week 4 Quarterback Who Should I Start? Brock Purdy, Daniel Jones, and More

Brock Purdy missed the previous two games with injury, but he is back in the lineup for Week 4. That has him on the minds of fantasy owners who have been without the QB more than they have had him this year. The quarterback in a Kyle Shanahan offense is always going to have fantasy value, and that's especially true for a guy who has excelled in this system before.

Let's look at Purdy and then do a head-to-head quick-hit start/sit with four guys who have been compared to him often on the FantasySP Who Should I Start? tool. Most stats are from NFL.com.

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Brock Purdy, San Francisco 49ers vs. Jacksonville Jaguars

Even with Purdy out, the offense stayed successful throwing the ball. With Mac Jones under center, San Francisco threw for 279 yards on 7.2 per attempt in Week 2 and 284 yards on 6.9 per attempt in Week 3. That efficiency is right at league average, a great outcome at that volume, especially with a backup QB in the game.

Purdy did more of the same when he played in Week 1, throwing for 277 yards on 7.9 yards per attempt. There's no reason to expect anything different as he steps back into the lineup. The 49ers are without injured skill players, like Brandon Aiyuk and George Kittle, but it hasn't mattered; the ball still moves.

Jacksonville has been very good as a pass defense to start the year, allowing the seventh-fewest yards per pass attempt while sitting right in the middle in fantasy points given up to quarterbacks. The Jags were among the worst pass defenses in football last year, so this is a big improvement.

I still view Jacksonville as a middling pass defense and think the numbers will get back there with more time, and that makes them a somewhat vulnerable team in fantasy. An efficient offense in San Francisco can have a good game against the Jaguars.

Daniel Jones, Indianapolis Colts @ Las Angeles Rams

Jones has had a phenomenal start to the season, looking different from any other time in his career. Even in his best season in 2022, Jones averaged 200 passing yards per game and 6.8 per attempt. This year, he's at 272 yards per game and 9.3 per attempt through three games.

That will likely regress as we get more games, but Jones is having a stretch like he never has before; something is different. He is also doing good work on the ground, having accumulated 55 yards and three touchdowns. All that adds up to put Jones at QB4 heading into Week 4.

The Rams are a tougher matchup. They have allowed the eighth-fewest yards per pass attempt, though they are in the middle in terms of fantasy points given up to QBs. Los Angeles was expected to have a formidable defense, so I'm believing in their chances to continue being stout.

Advice: This is about as 50/50 as it gets. Both Purdy and Jones have middling matchups that could be a little tougher. Because he runs the ball more, I will give the slight advantage to Jones, but I could be swayed either way. Start Daniel Jones over Brock Purdy by the slimmest of margins.

Baker Mayfield, Tampa Bay Buccaneers vs. Philadelphia Eagles

The Bucs have a bit of a tougher matchup here and have also been dealing with injuries to the offense. Chris Godwin and Tristan Wirfs will make their season debuts, much-needed reinforcements, but Tampa is still without Mike Evans and Jalen McMillan in the receiving group and their right tackle and right guard (Luke Goedeke and Cody Mauch, respectively).

Philadelphia has allowed the 12th-fewest yards per pass attempt, but that number is a well-below-average 5.7. They gave up the fewest yards per attempt last season and still have many of the main pieces from that group. I'm not excited about using anyone against the Eagles.

Mayfield has struggled a bit, averaging 206 passing yards per game on 6.2 per attempt. He's also completing just 61.6% of his passes after being up at 71.4% last season; a few tougher matchups and guys missing with injury have made for a rough go of things for Mayfield early.

Advice: Start Brock Purdy over Baker Mayfield.

Dak Prescott, Dallas Cowboys vs. Green Bay Packers

Like Mayfield, Prescott hasn't been able to find consistent footing in the early season. He is averaging 266.7 passing yards per game, a good number, but that's coming on just 6.3 yards per attempt, a well-below-average number (league average is around 7.0).

He struggled against a tough Eagles team in Week 1 while playing better against the Giants in Week 2, but then Prescott had an easier game against the Bears in Week 3 and was underwhelming, racking up 250 passing yards but taking 40 attempts to get there (again, just 6.3 per attempt).

With CeeDee Lamb out a few weeks, I'm not looking to count on Prescott, and that's especially true in a tough matchup. The Packers have allowed the fewest yards per pass attempt and second-fewest fantasy points to quarterbacks. That's not a team to go after with any quarterback.

Advice: Start Brock Purdy over Dak Prescott

Geno Smith, Las Vegas Raiders vs. Chicago Bears

This is a better matchup: Chicago has allowed the fifth-most yards per pass attempt and the third-most fantasy points per game to quarterbacks. The Bears got torn apart by the Lions in Week 2, a big part of those poor numbers, but they also don't project to have a great defense so it's easy to trust the numbers.

Smith has two big games and one slow game on the season, getting shut down by the Chargers in Week 2 but looking better against weaker competition in the Patriots and Commanders.

Smith is a fine streaming quarterback in the right matchups, and this is one of those games. When it comes down to him versus Purdy, I have to go with the San Francisco QB because he's in a better passing game. Smith is still a decent option in Week 4.

Advice: Start Brock Purdy over Geno Smith