The door is cracked open, probably as wide as it will ever be. What’s left is for the Raiders to kick in the door — and perhaps Marshawn Lynch will be back in Oakland, wearing silver and black.

This is a good idea on multiple levels, far more than just the publicity. Yes, it would be a great story, the Oakland kid returning home. But, beyond that, Lynch would be the franchise’s most dominant back since Bo Jackson.

Lynch to the Raiders is neither a pipe dream nor a sure thing. It could happen, but it’s complicated.

Lynch, 28, has one more year on his four-year, $31 million deal. He is reportedly negotiating an extension with Seattle, Seahawks coach Pete Carroll said in a radio interview Tuesday. Per NFL Network’s Ian Rapoport, the Seahawks are talking about doubling Lynch’s salary to $10 million next season and possibly keeping him in Seattle for the rest of his career.

The bigger question might be whether Lynch is interested in remaining with the Seahawks. According to multiple people close to Lynch, he hasn’t been happy in Seattle and wouldn’t mind leaving the franchise.

He was unhappy enough to hold out from training camp in July. He was reportedly unhappy about Seattle’s trade of receiver and buddy Percy Harvin. He reportedly doesn’t see eye to eye with Seattle offensive coordinator Darrell Bevell — a situation that could not possibly be helped by Sunday’s Super Bowl fiasco, when Lynch didn’t get the ball from inside the 1 with the game on the line.

Remember when the Seahawks were touting the running-back-by-committee approach, making room for Christine Michael? It stands to reason why friends of Lynch say he has felt underappreciated.

Of course, doubling his salary could change that. But it wasn’t that long ago such wasn’t considered an option.

Up until the end of the season and the playoffs, Lynch was expected to be on his way out of Seattle. His cap number next season jumps to $8.5 million. Not that long ago, that was thought to be to hefty price for a running back who will be 29 when the season starts, reportedly has a chilly relationship with his coaches and routinely causes a headache for NFL execs with his anti-media approach.

On top of that, Seattle can save $7 million by releasing Lynch, money figured to be needed for quarterback Russell Wilson’s pending raise.

It wasn’t until Lynch went Beast Mode on opposing defenses and on the media that the tide turned toward keeping him. His value is as high as ever, consisting of 1,306 yards and 13 touchdowns during the regular season and another productive postseason campaign. Plus his public battles with the media, and NFL policy forcing him to talk, have turned him into a folk hero.

Seattle outright releasing him now seems unlikely. But that doesn’t mean the relationship isn’t vulnerable.

And that’s where the Raiders should come in. Seattle management, as shrewd as any in the league, would rather get something for Lynch than release him. Raiders G.M. Reggie McKenzie should be getting an offer ready right now.

How many All-Pro players want to join the 3-13 Raiders? Lynch, who made second-team All-Pro this year, is the only one. The Raiders could score big points with their die-hard fans and possibly boost their momentum for a new stadium by landing such a name. That’s a break for the Raiders, one of the league’s best backs having a pre-existing love for Oakland.

“Are you kidding me?” a source close to Lynch said, requesting anonymity. “That would be a dream come true.”

“He’s got Oakland tattooed on his back,” said another source close to Lynch, putting it simply.

But mutual desire alone isn’t enough to get Lynch to Oakland. The Raiders don’t have much to give up in a trade, and draft picks are too important to a team with so many holes. So figuring out how to lure Seattle into a trade would be tricky.

This is where McKenzie can prove he is a factor in this league. The odds are against him, but the fit is there as is the slight window of opportunity. He could go a long way to showing his executive mettle by making it happen.

And here is why it is worth it: Lynch would be huge for Derek Carr’s development.

The Raiders’ franchise quarterback, in his second year, desperately needs a running game to take some pressure off him. And Lynch, one of the most feared in the league, would immediately become the No. 1 focus of opposing defenses.

Lynch is the highest- rated ball carrier in the league, per stats from Pro Football Focus, not counting pass-catching out of the backfield. He is also one of the best blockers at the position and leads the NFL in forcing missed tackles — skills that come in handy for a Raiders offensive line that’s had its issues with consistency.

The Raiders have a lot of needs, for sure. And younger, cheaper running backs are more desirable. But to get Lynch in his prime, if possible, is too good to pass up.

And since the Raiders have more than $60 million to spend in free agency, they could get Lynch and still fill other holes.

Lynch could be worth the price, too. In addition to being a productive and durable back, his marketability has never been higher. His swag has never been more embraced. His star is peaking. He even plays with an edge that fits the legacy the Raiders love to promote.

Just about everything about this says Lynch should be a Raider. This would be a good time for the Raiders — McKenzie and owner Mark Davis — to find a way to make it happen, to not let the complications stop it from happening.

Read Marcus Thompson II’s blog at blogs.mercurynews.com/Thompson. Contact him at mthomps2@bayareanewsgroup.com. Follow him on Twitter at twitter.com/ThompsonScribe.