Stein says Heat's Erik Spoelstra is the hot new threat in Coach of the Year race

Kim Klement-USA TODAY Sports

The last man to win NBA Coach of the Year honors from a non-playoff team was Doc Rivers with the Orlando Magic in 1999-2000.

Consider this your warning to take note of what's happening in Florida's other NBA city nearly two decades later.

Houston's Mike D'Antoni, Boston's Brad Stevens, Utah's Quin Snyder, Memphis' David Fizdale ‎and, of course, San Antonio's Gregg Popovich all remain prime contenders for the ultimate COY prize. Washington's Scotty Brooks, furthermore, has added himself to that group by masterminding the Wizards' recent turnaround.

Yet it's Miami's Erik Spoelstra who boasts the most irresistible case to score our nod for the second Trimester, given what legitimately ranks as an unprecedented in-season turnaround for a team that reached the season's halfway point on pace to win 22 games.

‎Entering Friday's disappointing showing in Orlando, Miami was on a 17-3 fairy tale of surge that (A) features what many are calling the most improbable 13-game winning streak in league history and (B) accounted for the best record in the NBA since Jan. 17.

What Spoelstra has done with an injury-riddled roster that had pundits and hoop know-it-alls howling for the Heat to tank when they were 11-30 is truly special. Yet those who know Spoelstra best will tell you he's obsessive about trying to find an edge, constantly studying any piece of data he can muster in the search for the best lineups and schemes and, as he's in the process of showing us, adept at squeezing month-to-month improvement from the group no matter who is wearing the uniforms.

As mentioned in Monday's Power Rankings, this is the complete list of players Spoelstra deployed as starters in those 13 wins in a row: Goran Dragic, Hassan Whiteside, Dion Waiters, Rodney McGruder, Luke Babbitt, Willie Reed and Wayne Ellington.

Spoelstra, incidentally, isn't the only coach from a non-playoff team who's building some COY momentum. ‎With Rick Carlisle ‎pushing the buttons in Big D like only he can, Dallas posted a 16-12 mark over the season's middle third, after the Mavericks had stumbled to a 6-20 start marked by countless injuries.

The improvement was the league's largest in win-percentage terms, from Trimester 1 to Trimester 2, with Carlisle's decision to move Seth Curry into the starting lineup paying particular dividends. When Curry starts, Dallas is 14-9.

We still say D'Antoni will be tough to beat at the COY finish line if the Rockets, currently on a 57-win pace despite coming into the season with such modest expectations, win at least 55 games. Voters are bound to be drawn to what D'Antoni's system has done for James Harden as well as the corresponding freedom he he's handed to his new star ... while revitalizing Eric Gordon and Ryan Anderson along the way.

It also has to be said that if the Celtics somehow overtake Cleveland for the East's No. 1 seed -- or if the Spurs wind up winning the West in their first season post-Tim Duncan and with injuries/inconsistency plaguing star swingman Kawhi Leonard's supporting cast -- Stevens and/or Popovich would suddenly reduce D'Antoni to mere co-favorite status.

Brooks is another name to monitor in the wake of the Wizards' surge from 12-14 in Trimester 1 to 21-7 in Trimester 2, which has thrust the Wiz into contention for a top-three seed in the East after a nightmarish 2-8 start.

But Spoelstra, frankly, strikes us as the most interesting what-if in the conversation. Seriously. Imagine if the Heat snag a playoff spot. What then?

Spoelstra has to get some COY votes in that scenario, considering Miami's playoff chances were down to 0.04 percent, according to ESPN's Basketball Power Index, when it was mired at 11-30.

Just before the Heat launched what our pal Micah Adams from ESPN Stats & Information likes to refer to as "the least likely double-digit win streak in NBA history."