It was a game that left the Seahawks kicking themselves afterward.

Only, on this day, if they’d really tried to do that they would have hit only air.

“This was an unusual game,” said Seattle coach Pete Carroll of the Seahawks’ 33-27 loss to the New Orleans Saints at CenturyLink Field on Sunday. “We had a really hard time getting out of our own way.”

And, much of the day, an equally hard time getting in the way of the Saints, who took a 27-7 lead into the fourth quarter and cruised to the victory. It was surprising not only in the mistake-filled manner in which Seattle played, but also because New Orleans had to play without future Hall of Fame quarterback Drew Brees.

Brees’ thumb injury compelled the betting line to shift from even at the beginning of the week to Seattle favored by as much as 5 1/2 points at kickoff.

Maybe the Seahawks got somewhat lulled to sleep by the idea that sitting at 2-0 they were now facing a team with a backup quarterback and maybe could just roll out of bed and roll to victory.

But the unusual nature of the day started before the game even began, when a ball thrown by Cody Barton as warmups ended hit Carroll in the nose.

“I just didn’t see it coming,” said Carroll, who wore a bandage on the nose the rest of the day (while declining to say if it was specifically broken).

Nor could anyone have really expected to see what happened next — a rash of errors that began on the first play, a penalty for an illegal block above the waist by Will Dissly that knocked Seattle back and helped result in a punt three plays later, and never ended.

The ensuing punt from usually reliable Michael Dickson went only 38 yards and Saints returner Deonte Harris made Nick Bellore and Ben Burr-Kirven miss tackles and then he was off to the races, going 53 yards for a score that set a sour tone for the day that never really got better.

After tying the game, the Seahawks then watched as Chris Carson lost his third fumble in three weeks (he was also part of another last week, and both led to eventual Pittsburgh touchdowns).

“I just need to protect the ball,” Carson said later. “That’s it.”

This time, Carson’s fumble directly resulted in a score as the Saints’ Vonn Bell scooped up the fumble and returned it 33 yards for a touchdown against a Seattle offense that mostly just stood and watched, seeming as befuddled by what was happening as everyone else.

A failed fourth down by Seattle on the next drive at the Saints’ 41 — one of many decisions Carroll admitted with rather unusual candidness that he’d like to have back — led to a short field for the Saints and a touchdown drive that made it 20-7.

The Seahawks then failed to use either of their two timeouts on the next drive, with the clock then running out when DK Metcalf hauled in a desperation pass for 54 yards, but short of the end zone. That left it 20-7 at halftime.

When the Saints drove 75 yards for a touchdown on their first drive of the third quarter — aided by a penalty against Al Woods on a field-goal attempt that kept the drive alive — the game was basically over.

“Just so many ways that this game could have been different,” Carroll said. “It’s very frustrating.”

Indeed, Russell Wilson ended up with one of his best statistical days, throwing for 406 yards and two touchdowns while running for two more — the first quarterback since 1950 to compile such a stat line.

And when the Carson fumble put the Saints ahead for good, New Orleans had just 32 yards on 13 plays with each drive ending in a punt.

But all the Seattle mistakes made all the stats moot.

And as left tackle Duane Brown pointed out, Seattle had played with fire a bit in its victories over the Bengals and Steelers, with turnovers, penalties and allowing some big plays on defense requiring the Seahawks to pull off a last-minute escape each time.

“We got away with some of that stuff the first couple of weeks,” Brown said. “But it bit us today.”

Wilson, as would be expected, tried to put a positive spin on the fact that so many of the errors were self-inflicted.

“When you’re going into a game like that, you’ve got to play clean football,” Wilson said. “The good thing is, we can do that.”

Seattle’s mistakes were so many that even injured players not suited up got into the act — the Seahawks were assessed a personal foul after recovering a fumbled Saints punt in the third quarter when injured safety Tedric Thompson went onto the field to celebrate.

But it wasn’t just dumb mistakes or bad coaching decisions that doomed Seattle.

The Seahawks also couldn’t pick up a single yard when they needed it on fourth down in the second quarter and the game still 13-7, emblematic of a running game that has yet to really click.

Seattle’s pass rush — which on this day was fully fortified with Ziggy Ansah’s debut — didn’t have any sacks and just two quarterback hits.

And the Seahawks were beset with shoddy tackling on a number of plays, most involving Saints running back Alvin Kamara, whom the Seahawks struggled to bring down all day.

Alvin Kamara (41) of the New Orleans Saints runs with the ball against Shaquill Griffin (26) of the Seattle Seahawks in the third quarter on Sunday, Sept. 22, 2019 at CenturyLink Field in Seattle, Wash. (Abbie Parr/Getty Images/TNS)

Carroll said of the early punt return that “we had four or five guys unblocked. We’ve got to make the tackle. Tackling showed up today.”

Said linebacker K.J. Wright: “It was very uncharacteristic of us. We are usually not that bad.”

And that’s the hope, that this was just a nasty blip on the screen.

Or, the Seahawks will hope, they were just due — it was the first home loss in September under Carroll. Seattle entered the game 15-0 in that scenario.

“We know we’re a better football team than that,” Brown said.

The Seahawks will go to Arizona next Sunday — the site of some of their worst moments — hoping to prove that after a game when they could hardly have been worse.