PHOENIX — Whenever Marshawn Lynch decides to leave the National Football League, one thing is for certain: It will be on his terms.

OK, two things.

He also won’t pop up six months later as an analyst for the NFL Network, and he is not going to kick Jon Gruden out of the color role on “Monday Night Football” in this lifetime.

When and how Lynch hangs up his cleats is the simmering question for the Seattle Seahawks and their boisterous 12th Man army that drowned out New England Patriots supporters at Media Day for Super Bowl XLIX on Tuesday.

Lynch showed up like a boxer arriving for a pre-fight weigh-in. He had back-slaps for friends he ran into on the floor, flashed a smile at the throng of reporters and then proceeded to say “I’m just here so I don’t get fined” 21 times before exiting his podium seat at exactly the five-minute mark that satisfied his league-mandated obligation.

The scene encapsulated the dichotomy that is the man who embodies his “Beast Mode” moniker.

On a team full of super-sized personalities, the Seahawks’ bruising running back is the enigmatic star. He guzzles Skittles like buttered popcorn, will sacrifice a paycheck to avoid talking to the media and has a penchant for grabbing his crotch at the end of a Richter scale-jarring touchdown run.

For Seahawks fans, the love affair with Lynch runs another level much deeper. On game days, “Beast Mode” themed party buses roll into parking lots, Lynch jerseys rival Russell Wilson threads and the 12th Man relishes the opportunity to kick-start a “Beast Quake.”

Since Lynch was acquired in a midseason trade from the Buffalo Bills in 2010, he has been the driving force behind a run-oriented offense — the yin to the Legion of Boom’s yang. He accounted for 26.8 percent of Seattle’s total yards from scrimmage this season.

“He’s the best back in the game,” Patriots nose tackle Vince Wilfork said Tuesday. “He’s going to run that ball, and he’s going to run it hard.”

Yet, it has been widely reported since last offseason’s holdout that the Seahawks are likely to part ways with Lynch after the Super Bowl because of his $7 million salary for 2015.

The pending separation took on more steam amid the team’s 3-3 start to the 2014 season, his frustration at good friend Percy Harvin being dealt to the New York Jets and reports of a crumbling relationship with coach Pete Carroll.

The Seahawks without Beast Mode is an unfathomable scenario for the team’s fans, who greet each new report spawned from an unnamed source with a defiant snarl.

The reality is Lynch is a 28-year-old wrecking ball of a runner in a league where 29 is often the precipice of the cliff for featured backs. The team did not overreact to his holdout because Carroll wanted to limit his offseason work anyway, and Lynch missed practice time this season with hip, calf and back injuries. There is also the inevitable salary cap strain that comes with consecutive trips to the Super Bowl, with Wilson and middle linebacker Bobby Wagner among those set for big offseason paydays.

“(Lynch is) one of the most competitive individuals I’ve ever been around,” general manager John Schneider said. “The way we managed (the holdout) was we just accept it. You can never get into a person’s heart or in their mind, you just have to adjust to what’s happening. Whether he was going to show up or not show up we had to be able to move forward. We wanted him to show up.

“Same thing — we hope he’s playing next year and he is going to attack it like he always is. His teammates love him. He’s a fun, jovial guy in the locker room. We want him around.”

The Seahawks can’t pay everyone All-Pro bucks — but can anyone truly envision Robert Turbin and Christine Michael splitting the backfield role in Seattle next season? Wilson has the media charm, but Lynch is the heartbeat of the offense and Schneider is well aware that his quarterback could be exposed minus a true lead back.

“I wouldn’t want to imagine what our offense would look like without him,” Seahawks offensive coordinator Darrell Bevell said.

With Seattle’s run to the Super Bowl and Lynch once again powering the offense, the NFL Network’s Ian Rapoport reported last week that the team is now prepared to work on a contract extension.

That would indicate the rumblings of off-field issues with the front office were greatly exaggerated, which would not shock anyone. Those reports came through the lens of the national media, which clamors for controversial topics and can’t wrap its head around Lynch’s mercurial personality.

National radio host Dan Patrick has bristled all season at Lynch’s treatment of the media, couching it as an affront to a fan base that wants to hear from its star running back.

That is a gross misunderstanding of the 12th Man.

A blue-collar fan base that has long bristled at the notion of being South Alaska to the rest of the country resonates with Lynch’s physical style and quietly defiant personality. They rush-order t-shirts out of his media session “quotes” — remember “I’m all about that action boss” from last year’s Super Bowl? — couldn’t care less if Lynch never answers a question about football and rush to his defense for every penny Roger Goodell takes out of his piggy bank, warranted or not.

Tired of Lynch’s act? Hardly, the “12s” are galvanized by his personality and if Lynch grabs a bottle of Fireball during the next championship parade, that’s all the fan interaction they clamor for.

By all accounts, Lynch is a great teammate, and his outspoken supporting cast is more than willing to fill the sound bite void.

Asked if Lynch would say he’s going to DisneyWorld should he win game MVP honors Sunday, cornerback Richard Sherman said, “I don’t know. He might say where he is really going, and it might not be DisneyWorld.”

We may not know where Lynch is going until his agent files retirement papers with the league.

It’s a good bet Lynch won’t be toiling in a reserve role with the Tennessee Titans at 33 years old so he can collect a paycheck and hang around the NFL scene. In fact, if Sunday proves to be his final game in a Seahawks uniform, it may be because he decided to walk away while he still can to kick it in retirement with his family back in Oakland.

Carroll and Schneider will huddle and chart their offseason course upon returning to the Northwest next week. They have teamed to build one of the league’s youngest, deepest and most talented rosters. They know Lynch’s role in the offense and in the locker room, and his unspoken connection with the fan base. They also know the tread on the tires is wearing thinner by the carry.

“He just takes great care of himself,” Schneider said when asked about the shelf life of running backs. “Down in San Francisco, he works out hard. Every time he goes away and we haven’t seen him for a while he comes back looking quicker than he was before. I have no idea — I think the sky is the limit really.”

It may be a drama that plays out deep into the offseason, but if Lynch wants to keep toting the rock, look for Schneider to find a two-year deal in the coffers.

Just don’t hold your breath awaiting the press conference.