Sun Life Stadium, in recent years, has been neither sunny nor lively — at least for fans of the home team.

But in the deciding moments of the Dolphins’ victory against St. Louis two Sundays ago, the place was rocking.

“It’s probably one of the first times in a while you could actually hear our fans cheering us on,” Dolphins punter Brandon Fields said.

Added center Mike Pouncey: “Right now, we’re playing good, so you can tell the energy of the stadium. I told one of my family members, it’s so different than last year.”

Relevance, hope and good quarterback play will have that effect — particularly in a place that has seen little of any.

But with Ryan Tannehill’s emergence, Joe Philbin’s competence and a soft schedule’s acquiescence, the Dolphins have given their supporters reason to believe. If the season ended today, the Dolphins (3-3) would be in the playoffs for the first time since 2008.

“With the AFC wide open, I feel as though this team has a real shot to make the postseason,” said Shaun Moore, a 33-year-old Dolphins fan who drives from Orlando to Miami Gardens for every home game. “Combine the amazing early success of rookies and the ‘sick-of-losing’ type of attitude from our vets, I feel this team is ready to make a run.

“I am very optimistic right now with the direction ownership and this current coaching staff has us positioned.”

For the Dolphins, those green shoots of life couldn’t come at a better time.

Their issues at the gate are well-known; Miami’s average home attendance – 55,776 — ranks 31st in the league. TV ratings have been soft, although certainly better than when the season started.

And with a home schedule bereft of signature matchups (other than the usual AFC East rivals), the Dolphins probably will flirt with blackouts for much of the season.

That, in part, is a reflection of fan frustration having given way to apathy. And for some, it will take more than a promising start before they buy back in completely.

“I feel as if the amount of turmoil this fan base has gone through isn’t normal,” said Erick Borrego, a 25-year-old banker from Miami.

Borrego has rooted for the Dolphins since he was 9. He became a season-ticket holder in 2005, but in the years since, his team has gone just 50-69 (including the playoffs). Once a “wild-eyed fan,” Borrego admits he’s now a football pessimist.

That’s why he, like most of the Dolphins supporters who reached out to The Miami Herald for this story, has adopted a wait-and-see approach to the team’s reversal in fortunes.

“A decade of mostly failure has made me jaded as a fan, waiting for the inevitable implosion,” said Matthew Infante, a 28-year-old project manager living in Colonia, N.J.

“However, I think it’s fair to believe the future is bright, assuming Ryan Tannehill continues to develop at this quite remarkable pace.”

Infante is the founder and former managing editor of ThePhinsider.com, the popular Dolphins blog. Kevin Nogle, an active-duty Army officer, now runs the website from Fort Hood, Texas — a sign that, despite their struggles, the Dolphins still have loyalties outside of South Florida.

That national reach will be on display this weekend. The New York chapter of the Dolphins Fan Club has bought hundreds of tickets in the 300 level to Sunday’s road game against the Jets, and the group has planned a massive tailgate.

Both teams involved appear to be at a crossroads. The Jets have lost three out of four and are taking on water. The Dolphins, meanwhile, aim for a winning record after seven games for the first time since 2003.

“I would love to see the Dolphins playing in January ... but one playoff berth isn’t enough to erase the entire decade,” Nogle said. “It’s next year that will be the key.”

Added Juan Hernandez, a 41-year-old season-ticket holder from Miami Lakes: “I’m beginning to look forward to going to the games on Sundays again to see what happens. It’s not the chore it’s seemed like at times in the years since [Dan] Marino’s retirement.”

That alone is reason enough to make some noise.

• The Dolphins added former Colts tight end Dominique Jones to their practice squad Tuesday. Jones, a 6-3, 255-pound rookie, played his college ball at Shepherd University, a Division II school in West Virginia. They cut linebacker Joe Holland to make room.

• Dolphins players on Tuesday visited with children involved with the Junior Achievement of South Florida, a Coconut Grove-based organization helping youths succeed in a global economy.