No offense to Brock Purdy.

I suspect, however, that Geno Smith — maybe even Drew Lock — could rack up impressive numbers playing QB for the 49ers.

Purdy leads the NFL in completion accuracy at 71 percent, and tops several other statistical lists.

The former Mr. Irrelevant from Iowa State has done an admirable job since inheriting the 49ers job in an emergency role last season.

But let’s be honest.

Purdy’s gig is pretty simple: Don’t screw it up.

Hand the ball to awesome runners, throw it to brilliant (and often wide-open) receivers, and go celebrate another score with your guys.

Brock Purdy is not the reason that the 49ers are a 12 1/2-point favorite over the struggling Seahawks ahead of this weekend’s rematch down in California.

That massive point spread has more to do with Purdy’s friends on the loaded 49ers roster — not to mention very recent history. 

The 49ers handed Seattle a 31-13 beatdown at Lumen Field less than two weeks ago.

Still.

In the league of “any-given-Sunday,” should a 6-6 team ever be almost a two-touchdown underdog?

The Vegas rationale: San Francisco’s weapons will be on full display, and the 49ers will overwhelm Geno and the injury-wracked Seattle offense.

Wipeout.

INDEED, it’s tough to make a case for the Seahawks in this NFC West matchup — which had a northern flavor for a few seasons, but has taken a dramatic turn south the coast.

It’s difficult to ignore those three 49ers wins last year, not to mention the very recent blowout.

Having said that, Pete Carroll hasn’t won a boatload of games (some as a distinct underdog) because he has no clue how to make adjustments.

I promise you that 49ers boss Kyle Shanahan and his position coaches have been raising their voices this week, making the Hawks sound like the Vince Lombardi Packers — and especially reminding the troops to forget, dismiss, ignore their 42-19 pounding of the 10-2 Eagles on the road a few days ago.

“Big wins mean nothing the morning afterward in this league,” they’ll be shouting.

Actually, they do mean something, especially if you’re the 49ers (9-3) and now have a serious shot at the NFC’s No. 1 seed. 

That sort of conversation, however, will NOT be the mantra in Santa Clara this week.

The 49ers should be all business in an effort to keep their flow going, while extending the Hawks’ misery into a four-game losing streak.

Carroll, ever the optimist, doesn’t see things like that.

Ever.

He can point to the Hawks’ dynamic play for long stretches in that 41-35 loss at Dallas — a game which saw the elite skills of DK Metcalf back on show with three touchdown catches.

The Cowboys have a terrific defense, but they couldn’t just overpower the Seahawks as the 49ers managed.

The 49ers' only three losses came in a row, when the team was stricken with key injures — notably to all-purpose weapon Deebo Samuel and bruising left tackle Trent Williams.

Among the things that stuck out in that win over the Eagles was Williams’ ability to blast open holes for Christian McCaffrey, and the entire line frustrating Philly by picking up blitzes.

Purdy generally had plenty of time to throw, and with the Eagles committing extra defenders to get pressure, there were miles of space downfield for Samuel, McCaffrey, receiver Brandon Aiyuk and tight end George Kittle.

The Birds had no answer.

SPEAKING of answers, that Vegas point spread this week suggests that Seahawks won’t fare any better than Philly.

Perhaps worse.

The Seahawks haven’t been such a dramatic underdog since a 13 1/2-point spread against Pittsburgh back in 2011, when Carroll was in his second season.

We know about the team Pete and GM John Schneider built back then — one bad pass (or bad call) from back-to-back wins in the Super Bowl.

Frankly, they’re busy creating another good team right now.

Plenty of holes have been filled, with some excellent drafts and, of course, the Russell Wilson trade.

The Seahawks, though, are not the finished article.

The interior of the offensive line was gouged by the 49ers last time out, Seattle couldn’t overly bother Purdy and his pals, and the game was never in doubt.

The Hawks still need more quality pieces, and many of their gifted young guys are learning on the job.

But the work goes on.

There are rumors around the NFL that Seattle is interested in Bears quarterback Justin Fields, who is younger and far more athletic than Smith.

And very possibly available.

Most of all, though, the Seahawks need to beef up where the 49ers are strongest — around the line of scrimmage.

That’s going to take some time.

Meanwhile, Pete surely will have SOMETHING in store for Shanahan and the 49ers on Sunday.

He’s still a wise old fox.

Shame there’s so much talent on the other side. 

Email: scameron@cdapress.com

Steve Cameron’s “Cheap Seats” columns appear in The Press four times each week, normally Tuesday through Friday unless, you know, stuff happens.

Steve suggests you take his opinions in the spirit of a Jimmy Buffett song: “Breathe In, Breathe Out, Move On.”