Another fourth-quarter flop to explain

SANTA CLARA – Here is how the 49ers (5-5) graded in Sunday’s 20-17 home loss to the Seattle Seahawks (5-5):

PASS OFFENSE: D+

Jauan Jennings’ massive rescue efforts (10 catches, 91 yards, go-ahead touchdown) fell short, as was the case in Week 3 at the Rams (175 yards, three touchdowns) as well as last season’s Super Bowl (TD catch, TD pass). Brock Purdy knew well enough to keep targeting Jennings, whose best effort was a third-and-11, 13-yard conversion in which he dragged four defenders to the Seattle 8, setting up his 3-yard touchdown catch with 9:33 to go. Purdy (21-of-28, 159 yards) got intercepted on a deflected pass he tried forcing into Christian McCaffrey (four catches, 27 yards). It’s alarming how minimal the production was from Deebo Samuel (four catches, seven targets, 22 yards; one run for minus-1 yard) and nothing from Ricky Pearsall (no catches, two targets). George Kittle (hamstring) was a pregame scratch, and it’s no coincidence the 49ers have lost 11 of their last 14 games when he hasn’t played.

RUN OFFENSE: D

As great as it is to see McCaffrey healthy and capable of 19 carries, he didn’t break any longer than 11 yards and finished with 79 yards, with minimal open lanes available. While Purdy got those lanes on his five scrambles (40 yards) and first-quarter touchdown run, the 49ers did not impose an intimidating rushing attack against a defense they owned in a previous six-game win streak. Instead, holding penalties (Jennings, Aaron Banks, Jake Brendel) nullified big gains. The 49ers tried compensating for Kittle’s absence as a blocker by deploying No. 3 tackle Jaylon Moore on several plays, and while that seemed to help, their lack of depth at tight end is a perennial problem.

PASS DEFENSE: F

Not only did this unit buckle on the Seahawks’ winning drive against Geno Smith (7-of-8, 54 yards), the defenders failed to spot him on a pair of late scrambles, the last of which was the 13-yard touchdown that sealed the 49ers’ fate. Said Fred Warner: “In the back end we have to be stickier and understand the situation: Geno’s going to want to come alive and extend plays.” Nick Bosa’s two sacks came at a price: he left in the third quarter with an injured left oblique/hip, possibly from compensating for his previous week’s right oblique/hip injury. Leonard Floyd’s sack on the final series was a positive sign, but clearly not enough. Isaac Yiadom’s interception on the first series after halftime came once Bosa and Floyd flushed Smith. With the Seahawks changing centers, the 49ers should have repeatedly blitzed up the gut, but when have they succeeded this season with extra pressure, instead deferring to predictable rush lanes.

RUN DEFENSE: F

Losing on a touchdown run by a 34-year-old quarterback is pretty damning. Losing fourth-quarter leads to the Rams, the Cardinals and now the Seahawks is downright embarrassing. Even though the 49ers stopped third- and fourth-and-1 runs for no gain to temporarily protect the lead, four minutes remained, which is an eternity for this season’s version of the 49ers. Stopping the Seahawks on third- and fourth-and-one with four minutes to go could have made this unit the hero. Instead, Seattle scored its second rushing touchdown, and the 49ers have now allowed 13 such scores on the season; Shanahan’s only team to allow more in an ENTIRE season was the 2021 squad (17). Terrible.

SPECIAL TEAMS: C-

Can’t blame them this time. Heck, even their most glaring mistake actually helped the 49ers, seeing how Jordan Mason’s muffed kick return resulted in the ball ricocheting off him and out of bounds for a 16-yard gain. Jake Moody made his only field-goal attempt (33 yards) after Yiadom’s interception. New punter Pat O’Donnell came away with just a 34.3-yard net average on three punts, his last resulting in a touchback rather than pin them deep for the final drive. Jacob Cowing left with a concussion after a 12-yard punt return, so if he needs time to recover, that could press Pearsall into action there.