It was in microcosm, sure. And it might have been mostly symbolic, yeah. But this day would be a small referendum, one way or another, on the Dolphins’ decision and direction at the most important position. That is why what happened Sunday here mattered for this club — no matter that the playoffs are out of play, and no matter that the opponent was all but an NFL imposter.

Ryan Tannehill outplayed Chad Henne.

It hardly qualified as en epic duel. Nothing about it stirred echoes of Tom Brady vs. Peyton Manning. This was just a rookie quarterback vs. another team’s journeyman in a game well off of the league’s marquee.

Yet it was more than that.

Henne was the four-year Dolphin and former starter who Miami decided wasn’t good enough, back for the first time to face the team that dumped him. Tannehill was his replacement, the kid drafted high to be a better answer.

Fun times

And if you don’t think Sunday’s 24-3 victory mattered, imagine if the opposite had happened? If Henne had risen and shone and Tannehill had failed and lowly Jacksonville had won. It would have been Miami’s worst loss of the season and it might have, for the first time, enflamed concerns about Tannehill.

Instead?

“It was fun!” said the rookie.

It was a quiet relief, too. And a little bit more cause for a Dolfan to not only hope in the future, but maybe to start to trust it.

This also was a very good day for Tannehill to be very good in part because the franchise’s 1972 Perfect Season team was on hand being honored at halftime on its 40th anniversary — the latest curtain call for the old ghosts who cast the constant, impossible shadow. This is the only club whose perfect past serves to make its far-from-perfect present seem that much worse.

Curmudgeonly Nick Buoniconti, the old linebacker, reminded the one-quarter-empty stadium how the old magical Orange Bowl used to be filled every Sunday, “and you cheered and you cheered and you cheered,” he exhorted the crowd, “and we won and we won and we won!”

Later Buoniconti privately allowed as how the current Dolphins — now 6-8 with Sunday’s win — “are not a good team.”

Fair enough. But what matters, what this season essentially is all about, is whether they will get there with Tannehill piloting. And that is a bit easier to feel positively about today than before, weak opponent or not.

Top-rated

Tannehill led this well-balanced rout of the woeful Jags every way a quarterback can. He was a sharp 22 for 28 for 220 yards. He had his first two-touchdown-pass game since October. He had the highest passer rating (123.2) of the season and thus of his career. A 37-yard strike to Brian Hartline on the first down of the second half, on a bootleg roll to his right, set the tone for a strong finish.

Tannehill even rushed for a season-best 52 yards, showing an athleticism that won’t supplant Robert Griffin III when one thinks of mobile QBs — but that will serve his overall game and development very well.

After a rough patch for the rookie, this game marked a reboot of sorts. Progress.

Along the way Tannehill even saw to it that Hartline surpassed 1,000 yards receiving for the season.

“Hopefully I get a good Christmas present,” the QB joked.