RENTON — When quarterback Russell Wilson threw a 35-yard touchdown pass to wide receiver Jermaine Kearse in overtime of Sunday’s NFC championship game, that play didn’t just send the Seattle Seahawks back to the Super Bowl, it instantly became one of the most significant plays in franchise history.

Yet that big play wouldn’t have been possible had Wilson not connected with wide receiver Doug Baldwin for 35 yards on third-and-seven one play earlier to extend the drive. Come up short there, and the Seahawks have to punt to Green Bay with Aaron Rodgers and his offense needing only a field goal to win the game.

Then again, that overtime drive never happens if backup wide receiver Chris Matthews doesn’t recover an onside kick late in the fourth quarter to set up Seattle’s go-ahead touchdown.

And there’s a very good chance that dramatic comeback wouldn’t have been possible had backup offensive tackle Garry Gilliam not caught a touchdown pass from punter Jon Ryan on a fake field goal early in the third quarter.

So many big plays had to happen for the Seahawks to come back from a 16-point deficit against the Green Bay Packers. And while those plays were all very different in terms of what happened and who was involved, the four huge plays highlighted above all had one thing in common.

On some of the most meaningful plays in one of the biggest wins in franchise history, at least one undrafted player was prominently involved.

There are plenty of impressive things that head coach Pete Carroll and general manager John Schneider have done to turn the Seahawks into a championship-winning franchise. But one of the most impressive is their ability to find, then develop, talent that other teams deemed unworthy.

It’s routine for the Seahawks to get big contributions from players who went undrafted out of college. Baldwin and Kearse, Seattle’s starting receivers this season, were passed over through seven rounds by all 32 teams in 2011 (Blkadwin) and 2012 (Kearse). Carroll doesn’t even think about how unusual it is unless somebody else brings it up.

“That’s kind of how it’s just been,” Carroll said. “We’re kind of numb to that right now, but it’s the facts. That’s why we talk about the work that John and his guys have done. It’s illustrated so many times with so many great examples of finding guys and getting them into the system, and then they play winning football for us.”

Sure Wilson was a third-round pick, despite a decorated college career, because of his size. But compared to many of his teammates who stepped up Sunday afternoon, Wilson was a hot commodity on draft weekend.

Before Gilliam could catch a touchdown pass that helped spark one of the greatest rallies in Seattle sports history, he went undrafted out of Penn State. Then had to fight for a roster spot in training camp as a rookie last summer.

And before Matthews could recover the onside kick Sunday, he had to hone his craft in the Canadian Football League for two seasons after going undrafted in 2011 and briefly spending time with the Cleveland Browns.

Matthews, who wasn’t even added to Seattle’s active roster until Dec. 6 — he spent most of the season on and off the practice squad — has never caught a pass in an NFL game. But he made a role for himself on special teams and ended up catching a bouncing ball that helped prolong the season.

(We’re leaving Ryan, who threw the touchdown to Gilliam, out of the discussion because almost all teams find their punters outside of the draft. Well except for teams that decide to take a punter in the third round, five picks before Wilson. … Sorry, Jacksonville Jaguars fans).

Kearse was so excited for his fellow undrafted receiver that on Monday he cut off a question to say, “Can I talk about the Chris Matthews play? That was huge.”

“I talk to Chris a lot. And just to see his progression, even when he was on the practice squad. And when he got elevated to the 53 (active roster), just to see him maximize his opportunities is definitely joyful because I talk to him a lot. “And for him to make a humungous play like that — that may be the play of the game right there. For him to get the onside and have a heads up play like that was truly incredible.

“It’s what Pete instills with his philosophy and this organization of just competing,” Kearse said. “He gives everyone an equal opportunity to compete and I feel like that brings the best out of players.”

It’s hardly unique for a football coach to preach competition, to tell veterans that no job is safe. But few teams, if any, are as committed to that philosophy as the Seahawks.

Year in and year out, undrafted players beat out those picked ahead of them for roster spots.

Whether it was safety Jeron Johnson beating out fifth-round pick Mark Legree in 2011. Or Alvin Bailey, who started Sunday’s game at right tackle, winning a roster spot last year ahead of seventh-round pick Ryan Seymour. Or fourth-round picks like defensive end E.J. Wilson and wide receiver Chris Harper not being able to out-play undrafted players at their positions.

As odd as it sounds, the Seahawks in a way are proud about the picks that don’t work out. Because it shows their willingness to give everyone an equal shot at playing time. Before the draft, the Seahawks send player agents a 12-page document that is essentially a recruiting brochure for undrafted rookies, detailing how the Seahawks have cut more draft picks under Carroll and Schneider than all but one team in the league.

“History has shown that the Seahawks keep and develop the Undrafted Free Agents they sign, even at the expense of draft choices,” the document concludes. “The Seahawks are more likely than most teams to give your Undrafted Free Agent play time in the preseason, giving your client the best opportunity to make the Seahawks or other team’s roster.”

For five seasons, we’ve seen how Schneider’s knack for finding hidden gems and Carroll’s openness to competition have helped turn the Seahawks into contenders. And on Sunday, in four very huge plays, undrafted players played pivotal roles in sending the Seahawks back to the Super Bowl.

John Boyle covers the Seattle Seahawks for the Everett Daily Herald. He can be reached at jboyle@heraldnet.com.