The 49ers defense put together their best game of the season last week holding Aaron Rodgers and the Packers to eight points. Now they face the second step of their three-game stretch of great quarterbacks when they head to Baltimore to face Lamar Jackson, who presents a whole different challenge than Rodgers.
The defense will have its hands full with the high-powered Baltimore offense and another quarterback capable of racking up big yards on the ground. Here are the six players to watch on the 49ers defense:
DL Nick Bosa

Bosa had his first sack in the month of November against Green Bay. Sunday night also happened to be the 49ers’ first game of the month against a non-mobile quarterback. On Sunday, the 49ers face Jackson who might be the best mobile quarter in the league. It’s possible it’s a trend for Bosa that he struggles getting to mobile quarterbacks, but he was able to continue getting pressure in those three games without a sack. The 49ers will need help from the entire front seven to contain Jackson and it’ll start with Bosa getting home from the edge.
DL Arik Armstead

Unlike Bosa, Armstead was able to get to both Kyler Murray and Russell Wilson, racking up 2.5 sacks in the three games. Armstead leads the 49ers with 10 sacks and has been a pleasant surprise in his fifth season. Armstead was able to pick up where Bosa couldn’t and will be needed against Jackson especially if Bosa struggles.
DL DeForest Buckner

Bucker also had two sacks against Murray and Wilson and didn’t seemed too phased by their ability to run. Buckner also could have a favorable matchup Sunday against back-up center Patrick Mekari who’s making the first start of his NFL career. Buckner, while not as productive in the stat column as last season, has been a presence up the middle of the 49ers line and could be in for a big day against the rookie center. Collapsing the middle of the line and blowing up the run game is vital to stopping the Ravens’ offense.
LB Fred Warner

Warner has been the 49ers’ best player on defense since Kwon Alexander went down with his injury. The last three games, Warner has 29 tackles, 3.0 sacks and two forced fumbles. He’s going to be an important piece at the second-level of the defense against an elite Baltimore running game. The Ravens thrive on creating havoc in the second level, and Warner can take away a lot of what they want to do on the ground and in the air with a strong effort Sunday.
CB Richard Sherman

While Sherman played well last week against the Packers, he was once again called for a couple of penalties that led to Green Bay’s only score of the night. Those penalties can’t happen against the Ravens. Sherman will have to play a disciplined game and not giveaway free yards to an offense that doesn’t need help. He’ll also need to help set the tone early. San Francisco needs to hit early and often, and that may start with the veteran corner on the perimter.
DT DJ Jones

Jones has been one of the unsung heroes on the 49ers’ defensive line. He doesn’t play a ton of snaps, but he’s a vital component to their run defense. That run defense needs to be at its best against Baltimore. Jones generally plays in the neighborhood of 50 percent of the snaps. The 49ers may want to get him on the field more often than that Sunday to try and turn the faucet off on Baltimore’s rushing attack.