1. Mobile QBs a conundrum for 49ers defense
The 49ers have remained a top 10 defense despite a bounty of injuries chiefly on their side of the ball. Top pass rushers Nick Bosa and Dee Ford are on I-R, as is DT Solomon Thomas and they were joined this week by cornerbacks Ken Webster and Jamar Taylor. Defensive coordinator Robert Saleh has done a masterful job of maintaining the unit's effectiveness despite having less talent at his disposal.
But if there's one particular issue they've had their share of problems with its defending the mobile quarterback.
"The kryptonite for the 49ers defense even before the injuries has been the running quarterback," said 49ers analyst and former CB Eric Davis in an appearance on 'One Bills Live.'. "A running quarterback is kryptonite to almost every defense, but Buffalo has a big, athletic quarterback under center who I like a lot in Allen.
"It'll be intriguing to see what the 49ers do because defensive coordinator Robert Saleh has had to battle against Kyler Murray and Russell Wilson in his own division. I would like to see how much he is going to commit to not let Josh Allen be the guy he is outside the pocket. That's the question in this game. How are you going to contain Allen and not let him get outside the tackle the box and make plays against you?"
In four games against mobile QBs, the 49ers have posted a 1-3 record. They're surrendering a completion percentage of 66.6 percent, a third-down conversion rate of 44 percent and seven of eight touchdown conversions in their red zone (87.5%).
Josh Allen currently ranks tied for fifth in total touchdowns (Kyler Murray) among quarterbacks with 29 and is averaging 275 yards passing per game.
2. Healthier on offense
San Francisco is getting more of its offensive weapons healthy as the third quarter of the regular season comes to a close. Last week, the Niners got WR Deebo Samuel back in the lineup and he delivered with 11 receptions for 133 yards in a 23-20 victory.
This week he'll have fellow receiver, rookie Brandon Aiyuk running alongside him as he returns from the Covid-19/Reserve list. Before going on the COVID list, Aiyuk in his last three games had 21 receptions for 281 yards and two touchdowns.
Additionally, San Fran's fastest tailback, Raheem Mostert also returned to the lineup last week. Although he did not have much production in the run game last Sunday, he did contribute an eight-yard touchdown run.
"Nick Mullens is more effective when Deebo Samuel, Brandon Aiyuk and Raheem Mostert are in the lineup," said NBCSports.com 49ers beat reporter Matt Maiocco in an appearance on 'One Bills Live'. "Those are three guys who certainly help. Aiyuk is a very polished wide receiver, so they have two young guys who do a lot of the same things. They can run routes at any level and they do a lot of passes behind the line of scrimmage with Samuel. And Mostert is a guy who is in scoring position anytime he touches the ball. But pairing Samuel and Aiyuk together is something Kyle Shanahan will be learning on the fly because they haven't been on the field much together due to injury."
3. Deep ball opportunities?
The Bills might be without one of their better deep ball receivers in John Brown, but there figures to be enough depth in Buffalo's receiving corps to take advantage of a secondary that's been susceptible to big plays in the passing game.
The 49ers defense have allowed a 44 percent completion percentage on deep passes, tied for the sixth-highest in the league. They've also allowed 641 deep passing yards this season according to NextGen Stats, good for sixth-most in the NFL.
The Niners have also allowed the fifth-most pass plays of 40 yards of more, surrendering eight on the season. Four of them have gone for touchdowns, tied for the third-highest total in the league.
Josh Allen has begun to target Gabriel Davis more in the absence of Brown in the lineup. Davis is averaging 5.3 targets in games without John Brown in the lineup. Last week he pulled in three of four targets for 79 yards and a touchdown and is now tied for the team lead in receiving scores (4).
"We asked the young guy to grow fast, come in here play fast, do his job," said Stefon Diggs. "He's been doing a great job all year. He's made some plays. We're going to look for him to make a lot more of them because we see a lot of potential in him. And that's just what the job calls for."
4. Surpassing 2019 marks
By season's end Josh Allen is certain to surpass several of the benchmarks he set as the team's starting quarterback a season ago. On Monday night he's almost assured of setting a new single-season passing yardage high against the 49ers.
Allen needs just 62 passing yards to surpass his passing yardage total for all of 2019 of 3,089 yards.
The Bills quarterback also needs just 100 yards passing on Monday night to tie for second in team history for most passing yards in the first 12 games of a season with Jim Kelly (3,127).
5. Managing with Mullens
When teams see an opponent that's forced to play their backup quarterback because their starter is injured they believe there will be a drop off in performance at the most important position. With 49ers starting QB Jimmy Garoppolo sidelined for almost half of the 49ers' games by a high ankle sprain, Nick Mullens has produced in comparable fashion to the man ahead of him on the depth chart.
Mullens will start again on Monday night and much like Garoppolo, is completing just over 67 percent of his passes. He's averaging almost eight yards an attempt much like the 49ers starter. And Mullens has six touchdown passes to Garoppolo's seven. The two QBs have even sacked close to the same number of times (Mullens – 13, Garoppolo – 11).
One area where Mullens has been decidedly better than Garoppolo has been in the fourth quarter. Mullens ranks a respectable 12th in the league in fourth quarter passer rating with a mark of 104.8. He's completed more than 71 percent of his passes in the final quarter of games this season. He's averaging almost nine yards per attempt and has four touchdowns against a pair of interceptions.
Where Mullens has struggled a bit however, is on third down. His completion percentage on third down (60%) is 10 percent lower than his overall percentage and he is even on touchdowns (3) and interceptions (3) for a pedestrian passer rating of 76.
San Francisco analyst and former DB Eric Davis believes those struggles are rooted in Mullens limitations as a passer.
"(Mullens) makes it very difficult to call a game if you're Kyle Shanahan," said Davis in an appearance on 'One Bills Live.' "It would have been impossible for Nick Mullens to have a good day against any secondary. Their passing game is played within an 18-yard bubble. And I'm not worried about him throwing beyond that 18-yard bubble because his arm isn't strong enough. This is not a Patrick Mahomes arm where I have to worry about chasing down a ball 70 yards in the air. He can't throw it far enough where an NFL DB can't catch up to it. So every opposing defense is playing everything downhill."
The struggles to convert on third down with Mullens have been especially troubling of late. In his five starts, the 49ers have converted just over 41 percent of their third downs, which is a decent success rate. But in their last two games, the San Francisco offense has managed to convert just six of their last 24 third down opportunities for just a 25 percent success rate.
Davis thinks with Deebo Samuel back and running the jet sweep motions, combined with the return of RB Raheem Mostert should support Mullens, but he doesn't seeing dramatically changing the complexion of the 49ers pass game.
"Raheem Mostert's return should help create some space in the passing game for Mullens, because his speed to the edge forces defenses to move immediately as a second level defender," Davis said. "But we all know that he doesn't have the arm that's going to push the ball down the field. So it'll continue to be difficult."
6. Coughing it up
If there's one area where the 49ers have not been proficient at all it's protecting the football. Through their first 11 games, San Francisco has 20 total giveaways with 12 interceptions and eight lost fumbles.
Only the Broncos (26), Cowboys (23) and Eagles (21) have more total turnovers than the Niners.
And the trend for San Fran has not been good of late. They have nine giveaways in their last three games alone.
Making matters worse is their offense hasn't done much with the takeaways their defense forces. The 49ers have scored the fourth-lowest point total off turnovers this season (28).
7. Big on the fullback
The 49ers are one of the few NFL clubs that make heavy use of a fullback, due in part to the talents of Kyle Juszczyk. San Francisco has run plays with a two-back set more often than all but one team in the league (New England).
Almost a third of the Niners plays (32.5%) are run with two backs and a tight end (21 personnel) and Juszcyzk is usually the second back on the field along with a primary ball carrier.
Seeing the fullback on the field doesn't necessarily mean the 49ers are running the ball as Juszcyzk is capable of making receptions out of the backfield.
8. Closing in on a rookie record
Bills kicker Tyler Bass has been in a groove the last several games as he has been good on each of his last seven field goal attempts, and on 11 of his last 12, with his only miss being a 61-yard attempt against Seattle.
With 95 points on the season, Bass needs just eight more points to set a Bills record for most points scored by a rookie. It's a record that has stood since 1964, when rookie kicker Pete Gogolak put up 102 points for the club's first AFL title team.
Bass should go into Monday night's game confident as he returns to Arizona's State Farm Stadium where he hit three consecutive field goal attempts from 54, 55 and 58 yards in Week 10.