Sometimes, it really is about the money.

It was for Byron Maxwell.

Here’s why he left Seattle, a budding dynasty that had appeared in the two previous Super Bowls, for the Philadelphia Eagles, who have appeared in two Super Bowls — in their history:

“Oh, cash flow,” Maxwell said. “All day.”

Hard to blame him. The Eagles offered Maxwell a six-year, $63 million contract before the 2015 season. The Seahawks, who took Maxwell in the sixth round of the 2011 draft, couldn’t match.

“They were close,” Maxwell said. “But I can’t make that back in my lifetime. So I had to go.”

He did. And on Sunday, he’ll be back.

Maxwell returns to Seattle for the first time in a different uniform. And he does so as a member of the Dolphins, who traded for him in March.

Maxwell said there are “definitely” no hard feelings for the people who run the Seahawks and that he remembers his four years there fondly.

He should. Maxwell was part of the best-named secondary in the league: the Legion of Boom.

Richard Sherman, Earl Thomas, Kam Chancellor and Brandon Browner were the other Boomers. Only Maxwell and Browner have left the team, which means Maxwell will see several of his best friends Sunday — although he will wait until postgame to catch up.

The Seahawks defense was excellent when he was part of the Legion. They led the league in fewest yards allowed in each of Maxwell’s last two seasons with the team.

And yet, he doesn’t see a huge gulf in talent between that group and this year’s Dolphins defense.

Maxwell said his new team “definitely” could reach that level.

“It takes great players,” Maxwell said. “Good coaches. To me, it takes depth too. The first guy’s got to be good, but the second guy has to be just as good. But we’ve got that here.”

Doing so would take a huge leap. The Dolphins had their worst pass defense in franchise history a season ago and surrendered the eighth-most total yards in the league.

So to make that jump, Maxwell needs to play like he did for the Seahawks in 2014 and not like he did for the Eagles in 2015. He never lived up to the billing in Philadelphia, and the Eagles traded him to Miami after just one season.

But the Dolphins want to get Maxwell back to doing what he does best: using his physicality to press at the line of scrimmage.

“He’s added a No. 1 corner for us,” defensive coordinator Vance Joseph said. “We didn’t have one before he got here after we let (Brent) Grimes go. He’s added a No. 1 corner for us; so far, so good.”

Since the trade, Maxwell has dropped at least 10 pounds and is running better than he did in Philadelphia.

Just three years ago, Maxwell and his coach Adam Gase were adversaries on the game’s biggest stage. Super Bowl 48 ended much better for the former than it did the latter. The Seahawks romped on Gase’s Broncos, 43-8, a result that still haunts the Dolphins’ first-year coach.

And when the two new allies discuss the game, it’s usually Gase who brings it up.

What does Gase say?

“He got blown out, dog,” according to Maxwell. “The No. 1 offense got smashed.”

That game still haunts Gase. Maxwell can relate. The year after the Seahawks lifted the Lombardi Trophy, they had to watch the Patriots do the same at their expense.

A month later, Maxwell was gone. But the feeling of celebrating a world championship with his former teammates remains strong.

“The confetti fall is the best moment,” he said. “That’s what you work for. That’s the feeling you want. That’s the feeling I want again. That’s it. Once you accomplish it, you’re like, ‘Man, this is what it is. This is what it feels like.’“