Matchups to watch: 49ers vs. Panthers

The Carolina Panthers defeated the San Francisco 49ers 10-9 in Week 10 as the defense clamped down and forced a career-worst performance out of Colin Kaepernick.

Kaepernick’s 7.7 Total QBR that day was his lowest in any game. How the Panthers were able to slow him is just one of the key matchups to watch Sunday.

49ers’ offensive line vs. Panthers’ pass rush

Kaepernick Passing in Week 10

The six sacks taken by Kaepernick in Week 10 were the most in his career, but he was also put under duress on an additional four dropbacks. Kaepernick went 0-of-3 passing and scrambled for 1 yard on those plays.

The Panthers finished the regular season with an NFL-high 60 sacks and the pass rush was only getting stronger as the season ended. The Panthers were able to sack Drew Brees and Matt Ryan a combined 15 times the last two games of the season, with Greg Hardy accounting for nearly half (7.0).

Crabtree, Boldin, Davis vs. Panthers’ secondary

It's worth noting that Michael Crabtree wasn’t available for the Week 10 game.

With Crabtree joining Anquan Boldin and Vernon Davis, the 49ers may be able to ease some of the pressure and better take advantage of a secondary that allowed opponents to complete two-thirds of their passes this season, the third-highest opponents' completion percentage in the NFL.

Kaepernick Passing This Season
With Crabtree, Boldin and Davis

Kaepernick has completed 64 percent of his passes this season when Crabtree, Boldin and Davis are all on field. If any of them leaves the field, his completion percentage dips to 56 percent.

Crabtree was targeted 13 times in the wild-card round against the Green Bay Packers, his second-most targets in a game in his career.

The 49ers' offense may have its hands full, but the Panthers' offense will also have some key matchups to win.

Cam Newton vs. the 49ers’ adjustments

Newton may have gotten the win in Week 10, but he finished the game with a season-low 50 percent completion percentage and a 19.6 Total QBR (third worst of season). Newton may have actually benefited too from an atypical 49ers strategy.

The 49ers sent four or fewer rushers 81 percent of the time this season (second highest in the NFL), but did so only 68 percent of the time in Week 10. Newton was solid against five or more pass-rushers (6-of-10 passing), but went 10-of-22 with an interception against four or fewer.

If the 49ers send rushers at their normal rates, Newton may struggle even more.

Panthers’ rushers vs. 49ers’ tacklers

One of the keys to victory in Week 10 was a 27-yard touchdown run by DeAngelo Williams late in the first half.

The play was notable because Williams was able to gain the final 16 yards of the rush after being contacted. Prior to that play, the 49ers hadn’t allowed 16 yards after contact on a single rush in any game since the start of the 2010 season.

The Panthers finished the game with 61 rush yards after contact, an average of 1.97 per rush. Both remain the most this season against the 49ers, who finished the regular season as the NFL's best in both categories.