The San Francisco 49ers fell to 1-4 on the season after losing to the previously winless Arizona Cardinals 28-18 Sunday.


The San Francisco 49ers now find themselves alone in the cellar of the NFC West. This, after falling 28-18 in Week 5 to the visiting Arizona Cardinals, who managed to secure rookie quarterback Josh Rosen his first win of his NFL career.

Rosen wasn't spectacular. Neither was the Cardinals offense, which managed just 220 all-purpose yards and 10 first downs over the four quarters.

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Meanwhile, the 49ers had 447 total yards of offense and posted 33 first downs. And lost by two scores.

That's what happens when turnovers get ugly. They did, as Arizona forced five Niners turnovers throughout the game. So one can bank on that factor being a key element in Week 5 grades for San Francisco.

Quarterback


C.J. Beathard didn't cost the 49ers a loss on the road versus the Los Angeles Chargers in Week 5. He played well there. Not exactly in Week 5.

Beathard passed a ton, partially based on the early injury to running back Matt Breida, going 34-of-54 for 349 yards, two passing touchdowns, a rush touchdown but also had two interceptions and two fumbles lost. With turnovers being a primary reason why the 49ers lost Week 5, Beathard won't get a good grade at all.

Grade: D

Running Back


Breida started off strong, getting the Niners on the board first after hauling in a 5-yard touchdown pitch from Beathard. Unfortunately for San Francisco and the offense, Beathard went down with an ankle injury at the end of the first quarter and didn't return, finishing with 56 rush yards on eight carries.

Filling in, No. 2 tailback Alfred Morris led the team with 61 yards on the ground on 18 carries. Fullback Kyle Juszczyk was also a major factor in the passing game, finishing with 75 yards.

It would have been a better grade for this crop had No. 3 running back Raheem Mostert not fumbled.

Grade: B+

Wide Receiver


Marquise Goodwin (quad) was out. So was Dante Pettis (knee). The 49ers have struggled all season with their receivers when Goodwin has been absent, as his ability to stretch the field has significant value.

Slot receiver Trent Taylor led all wideouts with seven receptions and 61 yards, adding a touchdown in the process.

Grade: D

Tight End


He started off slow, but George Kittle managed to get into the mix late in the second half, finishing the game with a team-leading 83 yards on seven catches, including this 45-yard catch-and-run off a screen:


Kittle is the 49ers' most reliable and dangerous weapon through the air. And it's not even close.

Grade: A

Offensive Line


Left tackle Joe Staley committed two penalties and also gave up one of the two strip-sack fumbles on Beathard, losing his contain on Cardinals EDGE Chandler Jones.

Beathard was sacked four times on the game, although two of those were clearly on the quarterback's shoulders. The 49ers' run-blocking efforts were solid enough, and pass protection for Beathard wasn't terrible.

Grade: B

Defensive Line


DeForest Buckner continued to be a force up front, finishing the day with three tackles, one for a loss, and three quarterback hits. Yet it was EDGE Cassius Marsh, not Buckner, who recorded San Francisco's lone sack in Week 5.

Marsh had his best game of the season against Arizona, picking up the sack and adding another three tackles in the process. That was Marsh's first sack of 2018 too, which probably says more about the 49ers' lack of an outside pass-rusher. They still need one in a big way.

At least Cardinals running back David Johnson wasn't much of a factor until late in the game.

Grade: B+

Linebacker


The lack of offensive plays by the Cardinals meant Reuben Foster and Fred Warner weren't particularly involved in the traditional stats, although both showed ranginess throughout the game and weren't overly affected by the poor tackling that plagued San Francisco last week versus the Los Angeles Chargers.

Grade: B

Secondary


Despite returning from a calf injury, Richard Sherman wasn't able to make the 49ers' defensive backfield better, instantaneously. No, in fact San Francisco's secondary weaknesses were revealed on its defense's very first stand.

The Cardinals' first offensive snap, actually:


Rosen hit fellow rookie, wide receiver Christian Kirk, for a 75-yard touchdown pass that made cornerback Ahkello Witherspoon look bad again. But safety Adrian Colbert didn't provide the necessary over-the-top coverage, allowing Kirk to easily get open.

Bad look both ways, and that set the tone for the Cardinals from there on out.

Grade: D+

Special Teams


Robbie Gould's franchise streak of 33-consecutive field goals made came to an end in Week 5. And Gould's point-after attempt following Breida's opening touchdown was also botched.

Oh, and punt-coverage units probably shouldn't bump into each other and touch the ball when it's stopped within the opponents' 5-yard line.

Yeah, special teams didn't look good for San Francisco versus Arizona.

Grade: D-

The 49ers now are tied for the worst record in the NFL through five weeks and lost to the lone team searching for its first win entering Week 5. It's hard to say if that says more about the Cardinals' own improvements or all that's wrong with San Francisco right now.

Perhaps both.

Regardless, things won't get easier for the Niners, as they travel to take on the 2-2-1 Green Bay Packers on Monday Night Football in Week 6.

Peter Panacy has been writing about the 49ers since 2011 for outlets like Bleacher Report, Niner Noise, 49ers Webzone, and is occasionally heard as a guest on San Francisco's 95.7 FM The Game and the Niners' flagship station, KNBR 680. Feel free to follow him, or direct any inquiries to @PeterPanacy on Twitter.