Getty Images

LeBron James led the Cleveland Cavaliers on a breezy run through the Eastern Conference playoff bracket last year, but he'll find a familiar challenger impeding his path in 2016.

Not totally familiar, of course, which is the whole point.

The rebuilt Miami Heat still have Chris Bosh and Dwyane Wade—James' main running mates during four straight Finals runs from 2011-14—but the more recent additions are what make the difference.

Back and (Almost) Better Than Ever

Jesse D. Garrabrant/Getty Images

"There's an argument the Heat will be the leading challenger to the Cavaliers in the East, and their books remain in good shape for the summer of 2016," ESPN.com's Kevin Pelton wrote, while giving the Heat an "A" grade for their offseason work. "It's not signing LeBron James, but it will do."

Goran Dragic, a midseason acquisition last year, inked a five-year, $85 million deal. Luol Deng is back. Hassan Whiteside, as stunning of a breakout star as the league has seen in years, will man the middle.

Alongside other mainstays such as Udonis Haslem, Chris Andersen and Mario Chalmers, the Heat have added Gerald Green and Amar'e Stoudemire on minimum contracts. Josh McRoberts will be looking to bounce back after a lost, injury-plagued season, and rookie Justise Winslow brings youth and versatility.

For what it's worth, James himself is impressed. He told Bleacher Report Radio:

I think Miami is doing some great things. They drafted the kid out of Duke, Justise. I think he’s going to be a really good player. They’ve added some big pieces. They signed Amare, I saw that. And Gerald Green is a big piece, I think, as well, coming from Phoenix. And the re-signing of Dragic, and C-B [Chris Bosh] coming back, one of my good friends, he’s coming back off of injury, and by getting D-Wade back, they’re going to be a contender.

Miami's depth looks almost superfluous, but it's actually a necessity. Wade missed 20 games last season, and his inability to hold up over a full slate is now a given. The Heat can rest him as often as they like now.

It's tempting to look at the Heat's performance last year and conclude this is a team nowhere near Cleveland's level. The Cavs crushed the conference after January trades solidified their rotation with J.R. Smith, Iman Shumpert and Timofey Mozgov.

After Jan. 15, Cleveland's net rating was plus-8.3 points per 100 possessions, far and away the best in the East. Miami had a negative differential during that same stretch (minus-1.5), and it feels like a hard sell to say adding Green, Winslow and Stoudemire is enough to make a real difference.

That overlooks the fact that the Heat's core players simply never got on the court together.

Lynne Sladky/Associated Press

Bosh and Whiteside were simultaneously healthy for just 18 games last season. Dragic didn't play a single minute with Bosh. And we know Wade was in and out of the lineup frequently.

Maybe that unfamiliarity means we should look skeptically at Miami's new roster. We can't yet know what potential chemistry issues there might be, and it's entirely possible a Bosh-Whiteside combination just won't work.

Step back a second and look at the talent, though. The entire second phase of Bosh's career has been built on his ability to adapt. Wade's off-ball game makes him an ideal companion for a combo guard such as Dragic, who is probably best as an initiator anyway.

Deng is an on-the-margins contributor who doesn't need the ball to make an impact, and the rest of the key rotation players—Green, Stoudemire and Whiteside in particular—have very clear roles.

So while it's not crazy to view Miami's uncertain chemistry as a negative, it makes more sense to focus on the potential upside.

James and the Cavs would be wise to take that approach—if only because the matchup issues the Heat present are uniquely problematic for them.

A Worthy Foe

Felipe Dana/Associated Press

There's no such thing as a James Stopper, but Deng would have to rank among the more accomplished James Slower-Downers in the league. Few wings have had as many reps against James as he has. As an occasional change of pace, Winslow could bother James a bit as well.

Miami's greatest weapon is the pick-and-pop action between Dragic and Bosh, which is admittedly a theoretical proposition at this point because, again, the two have yet to play together. But take what we know of both players: Bosh is as deadly as any floor-stretching big, and Dragic is a flat-out elite finisher at the rim.

He converted 69.1 percent of his shots at the basket last year, best among guards with at least five such attempts per game and nearly as good as James' own 69.7 percent conversion rate inside. Pay extra attention to Bosh, and Dragic will kill you with layups. Shade toward Dragic's drive, and Bosh buries a three.

There's no right choice, and the guys Cleveland will have to rely on to make those lose-lose decisions tip the matchup even more dramatically in Miami's favor.

Kyrie Irving and Kevin Love are among the poorest defenders at their respective positions, and they'll be the ones the Heat target relentlessly in those exact pick-and-pop scenarios. Barring miraculous improvement from both, Miami is going to eat Irving and Love alive with the league's most basic offensive set.

Will Dragic and Bosh have their work cut out for them against Irving and Love on the other end? Absolutely.

But if you think the Cavs are going to phase James out so they can run pick-and-pops with Irving and Love all game long, you've got another thing coming.

The Dragic-Bosh sets will put immense pressure on Mozgov at the rim, where he'll have to worry about Whiteside inhaling backdoor lobs and Wade ghost cutting along the baseline the second the big man strays from the basket to stop a drive.

It's comically early in the offseason to be talking about matchups and strategies—especially when injures (on both sides) will likely be the biggest determinant in how things play out. But even at this premature juncture, the Heat appear to pose a bigger threat to James and the Cavaliers than anyone else in the conference.

Pecking Order Intact

Ben Margot/Associated Press

The Chicago Bulls deserve a mention here, as new head coach Fred Hoiberg should improve the offense. But if we're talking about health as a wild card for Cleveland and Miami, the Bulls' recent history makes them an even bigger unknown.

Let's be clear about something else: Cleveland remains the favorite.

It traipsed through the East bracket last year without incident, despite losing Love early and wearing down throughout the run. The whole gang figures to be back once J.R. Smith and Tristan Thompson sign their respective deals, and the additions of Mo Williams and Richard Jefferson will make a difference.

As much as the Heat have improved, and as real as their ability to contend may seem, the Cavaliers are the surer bet.

But it's a conversation now, and at the end of last season, it didn't look like there'd be much to talk about in terms of challengers for James and his Cavs.

It's exciting (and narratively rich) that Miami is the team rising up to complicate James' quest for more titles. Already, the West features a half-dozen teams at least as good as the Cavaliers, and now there's an intra-conference foe stepping in to make James' job even harder.

And it happens to be the team he left behind last summer.

James can build a title contender all by himself, but the Heat's institutional resiliency and know-how means they can construct them almost as reliably. They won a ring before James, then two with him. Now, they're positioned pretty well to chase another after his departure.

Can we start the season now, please?

All stats courtesy of NBA.com.