Phoenix Suns rolling under interim head coach Jay Triano

Suns guard Devin Booker said he was shocked by his team’s firing of head coach Earl Watson after just three games, and he wasn’t the only one.

Pretty much the entire NBA was surprised to see Watson sacked so quickly — faster, in fact, than all but two other dismissals in league history.

That’s what happens when you tumble out of the gates with two losses of 42 points or more and the NBA’s worst net rating by a huge margin at minus 26.6 points per 100 possessions. (For reference, the Lakers led the NBA last season at a comparatively paltry minus 7.2 per 100.)

But even more shocking than the Suns’ shambolic start is their red-hot play under interim coach Jay Triano, whose record improved to 4-1 with an impressive 122-116 victory over the Wizards in which they rallied from 22 points down.

T.J. Warren scored 28 of his career-high 40 points in the second half, and Devin Booker added 22 for the Suns, who scored 35 or more in each of the final three quarters to earn a victory that would have been unthinkable a week ago.

“It shows we’re mentally tough,” Warren told AZCentral.com. “We’re growing and getting better day by day.”

And they’re doing it not only with a new coach but also without the gifted Eric Bledsoe, who was essentially suspended and will likely be traded after tweeting his dissatisfaction with the Suns’ disastrous start.

Much of the credit should go to Triano, a no-nonsense lifer who isn’t afraid to bench players to get his message across.

While still not great on defense, the Suns have improved their play on that end from 117.0 points allowed per 100 possessions under Watson to 102.0 under Triano — good for 13th in the NBA during that span. Per AZCentral.com, he’s also gone back to basics on offense with a more standard starting lineup featuring Marquese Chriss, a true power forward, rather than 6-foot-8 rookie Josh Jackson alongside fellow small forward Warren.

Beyond stats and strategy, the difference in basic effort is perhaps most noticeable of all. Terry Stotts, whose Blazers helped seal Watson’s fate with a 48-point thrashing on Oct. 18, could scarcely believe they were facing the same Suns 10 days later in a game that went down to the wire.

“I really am impressed with Phoenix,” he said. “They really turned it around in a short amount of time. They’ve really bought into what Jay is trying to do at both ends of the floor. They’re a much better team than they were the first time we played them.”

The turnaround is giving center Tyson Chandler flashbacks to 2004-05, when his Bulls recovered from an 0-9 start to make the postseason.

“I’m not putting that on this young team,” he told AZCentral.com after Wednesday’s comeback. “I’m just saying we’re playing the right way. That is where we are taking a step in the right direction.”