DAVIE, Fla. -- Miami Dolphins running back Reggie Bush walked into the media room with a smirk on his face Wednesday.

“Packed house,” Bush said with a grin. “I wonder why.”

Miami's rookie head coach, Joe Philbin, entered minutes later and also noticed a larger-than-usual media corps. It was quiet confirmation that the Dolphins finally are doing something right.

It’s been four years since the Dolphins have been this interesting. That was 2008, when former coach Tony Sparano led Miami to an unexpected 11-5 season and an AFC East title.

Since then, the Dolphins have pretty much been a bad punch line. This summer alone, Miami had to slog through a winless preseason and handle the Chad Johnson fiasco on national television during HBO’s “Hard Knocks.” A 1-3 start to the regular season also didn’t help things.

But the Dolphins are suddenly interesting again. They have won two straight with a talented rookie quarterback (Ryan Tannehill) and a physical defense. Many are wondering whether Miami is just a flash in the pan or potentially a surprise team in the second half of the season.

The Dolphins (3-3) are at a crossroads, and Sunday they travel to MetLife Stadium to face the rival New York Jets (3-4). This matchup will greatly affect the direction of both AFC East teams.

“It’s a big game,” the usually calm Philbin said. “No question about it.”

Added Jets coach Rex Ryan, “It’s a huge game for both teams. If it’s said otherwise, it’s not true, because nobody believes it. Everybody knows how huge this game is.”

Is Miami a contender or pretender?

This rebuilt Miami team wasn’t expected to compete for a playoff spot in 2012. But the division is mediocre and so is the AFC, and suddenly the wild-card spots are wide open for any teams that can get hot.

"It's a big game," Dolphins coach Joe Philbin said of Sunday's matchup with the Jets. "No question about it." Kirby Lee/Image of Sport/US Presswire

The veteran Jets have been there before. They went to back-to-back AFC title games in 2009 and 2010. It’s the younger, less experienced Dolphins who have to prove they are legit.

This is a golden opportunity for Miami to bury the Jets and send them packing for the season at 3-5. That is a record New York most likely wouldn't be able to recover from, especially with its best player (CB Darrelle Revis) and No. 1 receiver (Santonio Holmes) lost for the season.

If the Dolphins are legit, they won’t let New York “ground and pound” their defense. Miami’s run defense is fifth in the NFL, and another good performance would force the New York to go to its air attack and quarterback Mark Sanchez.

If the Dolphins are legit, they will establish Bush and their ground game on the road against a Jets defense ranked 30th against the run. The combination of running well and stopping the run has kept Miami in nearly every game this season.

If the Dolphins are legit, Tannehill will continue to show improvement after the bye. He struggled against New York’s defense in the teams' first meeting this season, throwing for just 196 yards and a costly pick-six. But Tannehill’s quarterback rating in the three games since have been 86.5, 92.3 and 112.0.

“I think he’s steadily improved each and every week,” Dolphins guard Richie Incognito said. “He’s done a really good job knowing what the defense is trying to do to us and putting us in the right protections and the right run calls.”

There are no excuses for the Dolphins, who have had two weeks to rest and prepare for their biggest rival. Miami nearly beat the Jets in the first meeting -- a 23-20 Jets overtime win in Week 3 -- and the Dolphins have seen enough tape to adjust to what went wrong.

Unlike the Jets, the Dolphins have been very fortunate with injuries and will enter this game virtually at full strength. Cornerback Richard Marshall (back) is the only player not expected to be available on Sunday. The Jets have injuries at linebacker (Bart Scott), defensive line (Sione Pouha, Kenrick Ellis) and running back (Bilal Powell and Joe McKnight).

A caveat might be the trash talk and emotion. These rivals simply don’t like each other. The back-and-forth between Dolphins players such as Bush and center Mike Pouncey and Jets players such as LaRon Landry and Aaron Maybin has made for a fun week. Landry has gone as far as to guarantee a win for the Jets.

Whether the trash talk leads to rough play remains to be seen.

“I go back to the game I saw on September 23 [and] it was a hard fought game by both teams,” Philbin said. “I didn’t think it was a dirty game. Players played hard, and I suspect that will be what happens this time around.”

The Dolphins have another thing going for them: Miami has never suffered a season sweep versus the Jets under Ryan. The Dolphins will be motivated not to let their biggest rival accomplish that feat.

“We know who we’re playing. This is a good football team,” Ryan said. “The fact that we’ve never beat them twice, that kind of gives us energy. The fact that we can go 3-1 in our division with two wins over Miami, that would be huge. So we see it as a real possibility.”

If the Dolphins are truly a contender, they will win this game and position themselves to make a push in the second half of the season. On the other hand, a loss by the Dolphins would throw them back in the pack of mediocre, sub-.500 teams.

It’s time for Miami to make its choice.