NFC Championship Preview: Detroit Lions at 49ers

The trenches are the key. Some matchups are a victory if the Niners can just avoid disaster, others must be won on critical downs to take the game.

The 49ers enter the conference championship having not played their best football in more than seven weeks when they routed the Eagles. San Francisco will need to recapture that level of execution Sunday against Detroit to make the Super Bowl.

The Niners are favored by seven over the Lions as a nod to the season.

The trenches are the key. Some matchups are a victory if the Niners can just avoid disaster, others must be won on critical downs to take the game.

INJURIES

Detroit left guard Jonah Jackson is out with a knee injury. He’s a 2022 Pro Bowler and was ranked as the fifth-best offensive lineman in the Divisional Round by Pro Football Focus. His replacement is 2nd-year pro Kayide Awosika, an undrafted free agent Detroit signed off the Eagles practice squad in September.

All-Pro center Frank Ragnow has an injured toe, ankle, knee, and back. Despite the injuries, he was a full go in practice on Friday.

For the Niners, Deebo Samuel had a full practice and is ready to play.

WHEN DETROIT HAS THE BALL

Detroit has been patient in slow-rolling Jahmyr Gibbs, waiting for the right moment to unleash him fully on the league. That moment is now.

Gibbs ranks 4th in the league in outside run efficiency. Against Green Bay, the Niners' run defense was 79% DVOA outside and -36.2% inside per FTN Fantasy.

DVOA measures production against the league average by down and distance. The lower the number the better on defense.

The 49ers defensive ends do a poor job of setting the edge, and the safeties did not play well against the run last week.

As with the Niners, the Lions like to use their skill players as blockers, they run out of three wide receiver sets frequently. Detroit’s receivers target the front seven to set up their OL against the secondary.

Therefore, the Niners must be proficient in this game in shedding blocks to make the tackle and swarm to the ball. They will also be looking for big games inside from Javon Hargrave and Arik Armstead against Ragnow and Awosika.

Gibbs averaged 8.2 yards per carry and had 114 yards of total offense against Tampa Bay. The Niners need to limit him, but Gibbs is a Detroit strength against the Niners' primary defensive weakness.

Passing is strength on strength. Jared Goff led the league in pass attempts in the middle of the field, over a quarter of his throws. However, the Niners are the league’s best at pass coverage over the middle.

Ben Johnson schemes his offense to layer the field vertically, with receiving targets about every five yards and a high-low game in the red zone. He also likes to flood zones with clear-out routes to free tight end Sam LaPorta underneath on 2nd and 3rd downs. The Niners must show solid discipline in zone coverage.

Johnson having so many ways to target the San Francisco linebackers makes it essential that the Niners safeties are sharp. Ji’Ayir Brown is expected to replace Logan Ryan in the starting lineup, who did not play well against the Packers.

An elite matchup will pit Nick Bosa against All-Pro tackle Penei Sewell. Given that Ragnow will be limited laterally, Wilks may look to employ stunts more frequently to get Bosa against Ragnow and Awosika.

Goff has improved against pressure since he’s been in Detroit, but it’s still an issue, he ranks in the middle of the league when facing pressure. The problem for Goff is his footwork evading pressure is poor.

San Francisco needs to pressure Goff as he leads the league in QBR from a clean pocket. The Niners front four can’t afford to go sackless as they did against Green Bay.

Detroit will look to target Ambry Thomas, the Lions move Amon-Ra St. Brown into multiple positions. Thomas could also be vulnerable to Jameson Williams deep, but Goff ranks 30th in the league in deep attempts.

What the Lions want to do is target St. Brown and LaPorta middle and run Gibbs wide. The Niners will hope to build a lead in the 2nd half to take away the run and play action.

Turnovers and red zone touchdown conversions will be vital. Detroit is top-five in the red zone. The Niners have intercepted Goff in four straight matchups, including three pick-sixes.

WHEN THE NINERS HAVE THE BALL

Job no. 1 for Brock Purdy is to play clean. With Detroit being so effective in the red zone, the Niners can’t afford to turn the ball over and give the Lions short fields.

The 49ers are undefeated when Purdy doesn’t throw a pick.

The matchup concern is at right tackle, Colton McKivitz against Detroit edge Aidan Hutchinson, who has eight sacks and 18 pressures in his last four games. At 6 foot 6, McKivitz is accustomed to a height advantage, but Hutchinson is an inch taller, quicker, and more agile. McKivitz uses violent hands to win, and Hutchinson counters that with spin moves.

Kyle Shanahan and Chris Foerster need to design a pass-protection scheme that gives McKivitz some help. They’ve been able to neutralize Micah Parsons, Myles Garrett, and Aaron Donald this year. T.J. Watt had three sacks but that was back in the season opener. Now, Hutchinson, with a trip to the Super Bowl on the line.

Detroit defensive coordinator Aaron Glenn is 4th in the league in blitz frequency. His most effective blitzer is safety Ife Melifonwu, who has 4.5 sacks in the last six games. The Niners struggled to pick up corner blitzes against Baltimore.

The 49ers have the league’s top offense against pressure, with Brandon Aiyuk the league leader when the quarterback is pressured at 14.4 yards per target. Detroit’s secondary is vulnerable, 30th in yards against per dropback and yards to wide receivers.

With Deebo Samuel healthy for the game, it’s also worth noting that Detroit is 28th in missed tackles.

The Lions have an excellent nickel corner in rookie Brian Branch, but their outside corners Cam Sutton and Kindle Vildor can be beaten. In their last five games, Detroit has given up nearly 10 catches for 178 yards to the number one receiver per game, and over 373 yards passing overall.

Detroit plays man coverage at the 6th highest rate in the league, both Purdy and Aiyuk excel against man.

In the run game, Detroit led the league in run defense DVOA and gave up only 11 explosive plays of 15 yards or more. That shouldn’t limit Shanahan from going to the run. Christian McCaffrey is the NFL rushing leader, Trent Williams is the league's top left tackle in the run game, and the Niners receivers are the best blocking group. Testing strength on strength should pay off.

PREDICTION (Playoff record 9-1)

Detroit’s offense is a serious threat with Gibbs finally unleashed. The loss of Jonah Jackson gives the Niner front four an opening to break up the Detroit running game and get to Goff. This game is where the Niners' massive investment in the defensive line has to pay off on the downs that matter most.

On offense, if Hutchinson can be neutralized the Niners will have their way but he's playing his best football right now. The Detroit secondary against the Niner receivers is a big mismatch. If Glenn blitzes to try to change that, Purdy and Aiyuk are at their best. I think this is high-scoring, and with the game on the line, Detroit can’t get the must-stop.

Sixty minutes to Vegas.

49ers 34 Lions 27