Seahawks RB Curt Warner, left, won the Star of the Year award in 1983 and WR Steve Largent followed two years later in 1985, the year he set the club record for receiving yards. / Seattle Sports Commission

In 1985, Seahawks coach Chuck Knox, inventor of diabolically mundane Ground Chuck offense, found a way for QB Dave Krieg to complete 79 passes to WR Steve Largent for 1,287 yards, breaking his own 1979 mark and setting a franchise standard that has lasted in Seattle for 35 years.

That was so long ago that fans actually attended games in person. Shoulder to shoulder. Maskless. Indoors.

It sounds made up, I know. But it’s true.

For a Knox offense to have set a positive pass-receiving record would seem unlikely. Not as unlikely, say, as Snacks Harrison medaling at the Winter Olympics in the slalom, but hard.

The key, apparently is to have a modest urge to throw to others.

Guess who was No. 2 in receptions that year? A running back. A good one — Curt Warner, with 47.  The No. 2 wideout was Daryl Turner (34 catches). The tight end was Charle Young (28).

The topic comes up because WR DK Metcalf is six yards shy of breaking the record of Hall of Famer Largent, which he seems destined to do Sunday against the 6-9 49ers (in Arizona, 1:25 p.m., FOX) in the regular-season finale.

“To break a record that’s been standing for so long, it’s a blessing just to be in this position,” Metcalf said this week. “It’s an amazing opportunity I have in front of me.”

In the first meeting with the 49ers at the Loo Nov. 1, Metcalf torched the damaged SF  secondary with 12 receptions and 161 yards in a 37-27 win. The Niners again will be without CB Richard Sherman — as well as CBs K’Waun Williams, Emmanuel Moseley and a cast of a thousand wounded  — who played in just five games because of a calf injury. At 32, he has said publicly he thinks his three-year tenure by the Bay is likely done.

So the depleted Niners seem to offer an opportunity for the Seahawks to put on video for playoff opponents some evidence that the explosive passing attack that dazzled the NFL in the first half of the season is still there; to say it is merely shrouded by choice, not inability.

After the 5-0 start, defenses began using two safeties deep to discourage shots to Metcalf and WR Tyler Lockett. In his searching, QB Russell Wilson hung on to the ball too long and forced matters, creating some turnovers. But the decision to throw under the coverage, coupled with a return to health in the run game, has made the offense a harder, if less flashy, out.

“We kind of went through a little hiccup in the middle of the season, but now we got it figured out,” Metcalf said. “Defenses have to find another way to beat us. If teams start going two-high, it’s gonna be interesting to see how how teams stop us.

“If you play two-high, we’re gonna run the ball. If you try to load the box, then we’re throwing it over your head. They they can pick their poison.”

The balance makes the offense less reliant on Metcalf. In the first eight games, he had seven of 90 or more yards. In the past seven, only one of more than 80 yards.

It’s worked out increasingly well for the offense. But if the change in emphasis becomes a more or less permanent feature of the offense over time, Metcalf in future seasons is going to have a difficult time reaching his other personal milestone beyond Largent’s mark — Calvin Johnson’s single-season NFL record of 1,964 yards in 2012.

“I kind of looked up (Largent’s) record last year, toward the end of the season,” Metcalf said. “So I knew it was going to be on the agenda this year to break it.

“I’ve got to start small with the Largent record, and then hopefully move on to Calvin’s record.”

That 700-yard difference is an epic climb. While Metcalf is a match for Megatron’s size, speed, power and hands, he bears the burden of being on a good team.

Johnson’s nine-year career (2007-15) was spent with the Detroit Lions, where he was often the only game-breaking option on a franchise that had two winning seasons in his time.

The Lions haven’t won a playoff game since 1991. Metcalf in his second season already has been in as many playoff games as the three-time All-Pro — two. In his record year, the Lions lost their final eight to finish 4-12 and broke a 30-year-old NFL record with 740 pass attempts (46.25 per game).

That’s how to get to a nearly unmatchable individual record in the NFL — be the best guy by far on a roster of perpetual mediocrity.

With the Seahawks about to enter their ninth postseason in 11 years under Carroll, a big believer in balance, Metcalf is going to get plenty of chances to be a star. But he has to share the stage.

Metcalf isn’t even leading the Seahawks in receptions.

Lockett has 88 catches, 11th in the NFL (Stephon Diggs leads with 120) and seven shy of breaking Doug Baldwin’s 2016 club record. Metcalf’s 80 are 19th.  Metcalf’s 1,282 yards are sixth, Lockett has 964, which is 19th. Metcalf has 10 TDs, Lockett eight.

That makes for one of the best tandems in the league. But as long as the band stays together, it’s not the best shot for a record solo act. Yet Carroll Friday was unwilling to put a lid on Metcalf’s capabilities.

“I don’t know what’s not attainable for DK,” he said. “He is such an extraordinary player. For us, he’s just getting started. I think the sky’s the limit for the kid. Because of his habits, his talent and and his mentality, he’s got everything that you’re looking for.

“So we shouldn’t set any boundaries for him at all.”

For a kid who turned 23 two weeks ago, owning a 35-year-old record is plenty for now.