The Kansas City Chiefs are getting most of the love and attention, but there's one other unbeaten team in the AFC. And although they've yet to play a contender, the 3-0 Miami Dolphins should be taken seriously. 

After all, teams that start 3-0 make the playoffs about 75 percent of the time, and the AFC wild-card race appears as though it'll be wide-open in 2018. 

A playoff appearance would be a stunning result for a Dolphins team that went just 6-10 last year before losing three of its most important players—wide receiver Jarvis Landry, defensive tackle Ndamukong Suh and center Mike Pouncey—in the offseason, but there's one player the Dolphins have now who wasn't there in 2017. 

His name is Ryan Tannehill. And if this becomes his breakout season, the Dolphins will have a shot. 

That's the difference a good quarterback makes. 

Without Tannehill last season, Jay Cutler, Matt Moore and David Fales threw a combined 20 interceptions while the Dolphins ranked in the bottom five in the NFL in passer rating. In this day and age, you won't survive with that kind of quarterback play unless you have a record-setting defense and/or a dominant running game. 

Even with Suh, Landry, Pouncey and—for a while—running back Jay Ajayi, the Dolphins possessed neither of those things. Ergo, they ranked in the bottom five in both points scored and allowed while losing double-digit games for the second time in three years. 

Early this season, Tannehill ranks in the top five among qualified passers with a completion percentage of 73.0, a yards-per-attempt average of 9.3 and a passer rating of 121.8. The Dolphins offense hasn't exploded like Kansas City's, but it's been steady and consistent, and Tannehill is coming off his best performance yet. 

Despite a slow start against the Oakland Raiders, the Dolphins scored 28 points in the final three quarters and 14 in the fourth in a comeback victory. Their 30-year-old quarterback completed all but six of his 23 passes for 289 yards and three touchdowns in a turnover-free performance. 

But Tannehill has been locked in all month.

He threw a perfect 75-yard rainbow touchdown pass to Kenny Stills in the fourth quarter of Week 1 against Tennessee Titans—a play that might have been the difference in a seven-point victory. He hit A.J. Derby on a semi-deep dart to put Miami up 20 on the New York Jets late in the first half of their Week 2 meeting. Against the Raiders on Sunday, he was money on another rainbow touchdown strike to Stills before finding a tight window on a deep completion down the right sideline to DeVante Parker as Miami was making a second-half comeback. 

Should this be surprising? 

Considering what he accomplished in Denver (two huge seasons with Peyton Manning) and Chicago (a career year for Cutler), Dolphins head coach Adam Gase was widely expected to get more out of Tannehill and his cohorts when he joined the team in 2016. Problem is, the offensive mastermind hasn't been able to spend much time with a healthy Tannehill.

The 2012 No. 8 overall pick missed 19 consecutive regular-season Dolphins games while dealing with two separate major knee injuries between December 2016 and the end of the 2017 season. But prior to that, there were some indications the Gase-Tannehill connection was bearing fruit.

The Dolphins have won 10 of their last 11 games with a healthy Tannehill under center. They've scored at least 26 points in eight of those games. During that span, Tannehill has completed 70.0 percent of his passes while throwing 20 touchdown passes to seven interceptions for a 105.4 passer rating. 

Those are Pro Bowl-caliber numbers and an indication that Tannehill's strong run prior to suffering that season-ending knee injury in December 2016 wasn't a coincidence. 

That doesn't mean he can carry the Dolphins on his own. He'll need to continue to get help from offensive tackles Ja'Wuan James and Laremy Tunsil, both of whom have played well (Tannehill has rarely been pressured this season but has excelled under duress anyway). And that Suh-less defense will have to continue to at least limit the damage against stronger opponents than the Titans, Jets and Raiders. 

They do have a strong and deep stable of pass-rushers, and third-year cornerback Xavien Howard looks like the real deal. Plus, there's room to grow for young recent first-round picks Minkah Fitzpatrick and Charles Harris, who have yet to make major impacts this season.

And while they'll have moments in which they'll miss Landry on offense, Gase is helping Tannehill make the most out of what he has to work with. 

"None of the Dolphin receivers' names pop off the roster sheet," wrote Pro Football Focus, "but [Gase] is playing exactly to their strengths."

Is it sustainable? And even if the Dolphins slow down to a degree, could they have enough going for them to make a run? Maybe so, because everyone is vulnerable in the AFC, especially in the East. The Dolphins look strong enough to bully the Jets and Buffalo Bills this season, and let's not forget that they beat and severely outplayed the New England Patriots without Tannehill in December. 

That juggernaut New England team is reeling after losing back-to-back games by double-digit margins for the first time in 16 years. The Dolphins can make a statement with a high-quality performance in Foxborough on Sunday. 

If they can pull that out, they'll essentially hold a 3.5-game lead over the Pats in the AFC East. But even if they don't, there are indications that their franchise quarterback is finally hitting his stride alongside their offensive guru head coach. 

If that's the case, you won't be able to count the Dolphins out anytime soon. 

Brad Gagnon has covered the NFL for Bleacher Report since 2012.