3 Takeaways from 49ers' Week 18 Win vs. Cardinals

The San Francisco 49ers' bid for the NFC No. 1 seed ended on Sunday, though not for a lack of trying.

They did what was needed against the Arizona Cardinals, notching a victory in the regular-season finale, but the Philadelphia Eagles also won to clinch the top seed and a first-round bye.

San Francisco did, however, claim the No. 2 seed and will have home-field advantage in the playoffs until/unless it faces Philadelphia.

It was a dominant performance by the 49ers, which roll into the postseason as hot as any team in the NFL. Rookie quarterback Brock Purdy played efficiently once again, the rushing attack battered the Cardinals' front seven, and the defense corralled an Arizona offense playing without its biggest stars, Kyler Murray and DeAndre Hopkins.

While there isn't a ton to glean from San Francisco dominating a four-win team just playing out the season, these are our biggest takeaways from its Week 18 win.

Another week yielded another strong game from Purdy, who finished 15-of-20 for 178 yards and three touchdowns. The 23-year-old is starting because San Francisco has lost quarterbacks Trey Lance (ankle) and Jimmy Garoppolo (foot) to injury.

Head coach Kyle Shanahan recently noted that the 49ers are still hoping to have Garoppolo back for the NFC Championship Game or the Super Bowl, should San Francisco make it that far.

"That's still the goal," he told reporters. "He's not out there running and stuff like that, so it's still a little ways."

Having Garoppolo back would be great for insurance purposes, but San Francisco has no need to reinsert him into the starting lineup. Purdy, who was taken with the final pick in the 2022 draft, has proved himself capable of leading Shanahan's offense to success.

This marked the Iowa State product's sixth consecutive game with at least two touchdown passes and San Francisco's fifth in six weeks with at least 33 points. It's about more than just numbers, though, as the young signal-caller continues to show confidence, poise and a thorough understanding of what San Francisco wants to do offensively.

While Sunday's game was largely meaningless for the Cardinals, it's worth noting that Purdy made it through another contest without showing any signs of approaching the dreaded rookie wall.

The 49ers have been on a tear with Purdy under center. Barring another unfortunate injury at quarterback, Garoppolo's time as the starter should be over.

Arguably, the biggest positive of Sunday for San Francisco was that it saw the returns of running back Elijah Mitchell and wideout Deebo Samuel.

Mitchell has been out since Week 12 with a knee injury, while Samuel has been out since Week 14 with knee and ankle issues.

Samuel didn't do a whole lot in his return (two catches for 20 yards and one four-yard carry), but his presence on the field was a welcome sight. He remains one of the league's most dynamic receiving/rushing threats, and he'll be a huge asset in the postseason.

Mitchell may be a bit of a luxury with Christian McCaffrey in the lineup, but he was phenomenal as a complement against Arizona. The second-year back out of Louisiana, who has landed on IR twice this season, carried five times for 55 yards and two touchdowns.

The 49ers have been getting plenty of offense without Mitchell and Samuel in the lineup, but their return ahead of the postseason adds more firepower to one of the most complete and balanced teams in the NFL.

With steady quarterback play, an elite defense and a bevy of potent (and healthy) offensive playmakers, San Francisco is built to win just about any contest in the 2022-23 postseason.

The 49ers head into the postseason on a nine-game winning streak, thanks largely to a spectacular defense. They came into Week 18 second and first in yards and points allowed, respectively. And the backline was fantastic again against the Cardinals.

Any NFC teams looking to this game for ways to attack the 49ers defense will largely be left empty-handed. The exception is a trick play Arizona ran early in the first quarter that caught the opposition napping.

Facing 2nd-and-7 on the opening drive, a pitch-throwback play allowed quarterback David Blough to find wideout A.J. Green for a shocking 77-yard touchdown strike:

That touchdown marked about the only negative takeaway for the 49ers. And while it was only one play, it's something San Francisco must note.

The 49ers have one of the most efficient, aggressive and physical defenses in the league, and if opponents can find easy yards against it, they're going to take advantage.

Not every opposing receiver will be capable of making the amazing catch Green did, but this probably won't be the last time San Francisco sees a trick play run against it in January.

The 49ers will have to remain cognizant of potential trickery because it worked on Sunday. In a close game with a chance to reach the Super Bowl on the line, it could be much more costly than it was against Arizona.