SANTA CLARA, Calif. — Dave Birkett grades the Detroit Lions in their 34-31 NFC championship game loss to the San Francisco 49ers on Sunday at Levi’s Stadium.

Quarterback

Jared Goff played a solid first half while staking the Lions to a 17-point lead but — like the rest of the team — didn’t deliver in the final 30 minutes when the game was on the line. Goff fluttered passes at several critical times Sunday, including a deep shot to Josh Reynolds on a throwback pass in the first half. He missed throws to Reynolds and Amon-Ra St. Brown on fourth downs in the second half after getting flushed out of the pocket, and he threw wide of an open Jahmyr Gibbs on a would-be touchdown when the Lions settled for a field goal on their final drive of the second quarter. Goff finished a respectable 25-for-41 for 273 yards with one touchdown and did not have a turnover for the third straight game, though he and Gibbs weren’t on the same page on the handoff before Gibbs’ fumble. Grade: B-minus

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Running backs

Gibbs and David Montgomery combined for 138 yards and two touchdowns on 27 carries Sunday, though they managed just 32 yards in the second half. Gibbs froze Ji’Ayir Brown with a nifty dead-leg on a 10-yard run for a first down and he showed good vision cutting back on Tashaun Gipson on his 15-yard touchdown run. Gibbs also converted a third-and-12, but his second-half fumble on the first play of a possession led directly to a 49ers touchdown. Montgomery (15 carries, 93 yards) scored on a 1-yard run in the first half and set the tone early with his physical rushing style. Grade: B

Receivers/tight ends

The Lions had a batch of uncharacteristic drops among their other unforced mistakes Sunday. Goff’s throw on fourth-and-2 in the third quarter was low and away, but it hit Reynolds’ right forearm, and Reynolds had another drop late in the third quarter on a would-be third-and-10 conversion. St. Brown also had a late drop, though he caught seven passes for 87 yards and converted four third-and-longs in the first half with catches of 13, 11, 23 and 9 yards. St. Brown and Reynolds had key perimeter blocks on Gibbs’ 15-yard TD run, and St. Brown made All-Pro linebacker Fred Warner whiff on a tackle on his third-and-10 pickup in the second quarter. Jameson Williams showed off his speed on a 42-yard touchdown run, splitting two defenders at the line of scrimmage and pulling away from a tackle near the end zone. Williams also made a strong catch on his 3-yard touchdown, though he was fortunate his bobbled catch wasn’t an interception. Grade: C

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Offensive line

Goff was blessed with a strong pocket most of the game. He took two sacks, one when Nick Bosa came unblocked off the edge on a miscommunication and the other when Bosa steamrolled Dan Skipper. But Taylor Decker and Frank Ragnow allowed pressures — to Bosa and Arik Armstead, respectively — on the Lions’ fourth-down incompletions, and the running game dried up in the second half. Ragnow and Graham Glasgow opened a Mack truck-sized hole on Montgomery’s 15-yard run on the opening drive and Ragnow was out front blocking on Williams’ TD run. Penei Sewell and Sam LaPorta had key blocks on a bubble screen to St. Brown that went for 13 yards and Glasgow and Ragnow had the big blocks on Montgomery's 14-yard run in the second quarter. Grade: B-plus

Defensive line

Josh Paschal made the defensive play of the first half for the Lions, tipping a Brock Purdy pass at the line of scrimmage that resulted in a Malcolm Rodriguez interception. Paschal (two tackles) also stopped Deebo Samuel for a 3-yard loss on an end-around on the fourth play of the second half. Aidan Hutchinson tipped two passes at the line of scrimmage on the opening drive; the second likely prevented a long pass after Brandon Aiyuk got Cam Sutton turned around on a timing route. Hutchinson did not have a tackle, though, and the Lions didn’t get enough consistent pressure on Purdy. Alim McNeill had one sack, and Tyson Alualu split another with Ifeatu Melifonwu. Grade: B-minus

Linebackers

Rodriguez saw his most significant playing time since early in the season after Derrick Barnes left in the first quarter with a right knee injury. He had six tackles, including one for loss, to go with his interception, but also overran two plays that went for first downs. Alex Anzalone closed the best season of his career with a strong game. He had a team-high nine tackles, including a nice one-on-one stop on Christian McCaffrey on the 49ers’ first play from scrimmage, and one quarterback hit. Jack Campbell set a strong edge when McCaffrey was stopped for a 1-yard loss on the 49ers’ opening drive, and shot a gap to haul McCaffrey down for no gain in the second quarter. But the 49ers finished with 155 yards rushing, the second-most yards the Lions allowed all season. Grade: B-minus

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Defensive backs

The Lions have some work to do in their secondary this offseason. Cam Sutton had a rough second half of the season and was subpar again Sunday. He was lucky not to get beat for a long gain on one of Hutchinson’s deflected passes and he, C.J. Gardner-Johnson and Jack Campbell missed tackles on McCaffrey’s 28-yard catch-and-run in the first half. Sutton also missed a tackle on a hitch to Samuel that went for 9 yards, dropped a potential interception in the end zone and gave Brandon Aiyuk too much cushion on his touchdown catch on the same drive. Kindle Vildor (six tackles) also had a would-be interception glance off his hand, then his facemask, on a 51-yard field-flipping catch in the third quarter. Brian Branch combined with McNeill on a tackle-for-loss in the red zone, but Melifonwu let Purdy slip out of a sack and scramble for a first down in the second half. Grade: D-plus

Special teams

Jack Fox bombed a 74-yard punt in the second half, but Chase Lucas’ momentum carried him just across the goal line when he tried to down the ball inside the 5. The Lions didn’t have many opportunities in the return game, though Donovan Peoples-Jones made one tackler miss on his lone punt return. The 49ers kept most of their starting defense on the field on the Lions’ first punt, a tip of the cap to the Lions’ success on fakes. And while Michael Badgley made his only field goal from 21 yards, the Lions’ lack of faith in their kickers from longer distances was a problem all season long. Grade: B-plus

Coaching

I like Dan Campbell’s aggressiveness. It's part of the Lions' attitude and identity. But Campbell was a little too loose with his fourth-down decision making Sunday. The Lions failed to convert two fourth downs from inside field goal range, and those missed points were the difference in a three-point loss. The Lions gave life to a 49ers team still reeling from a bad first half when they failed to convert on fourth-and-2 in the third quarter, and I would have attempted the game-tying field goal on fourth-and-3 in the fourth quarter. The analytics back Campbell’s approach, so his decisions are not indefensible, but the end result certainly hurt the Lions’ chances of advancing to the Super Bowl. Campbell and his staff deserve credit for having players ready to play in a dominant first half, but ultimately they couldn't stop their team's tailspin late in the game. Grade: D-plus

Contact Dave Birkett at dbirkett@freepress.com. Follow him on Twitter @davebirkett.

This article originally appeared on Detroit Free Press: Detroit Lions grades v. 49ers: Dan Campbell's decisions prove costly