MESA, ARIZ. ? Let’s see, what word best describes the Phoenix Suns’ firing of coach Frank Johnson on Wednesday?

Unjust? No, not strong enough.

Indefensible? Getting there.

Gutless? There you go.

General manager Bryan Colangelo can spin until his monogrammed shirts and Italian suits are drip-dry, but don’t be fooled by the predictable blather.

Johnson didn’t fail the Suns; the Suns failed Johnson.

Good luck, Mike D’Antoni. But I wouldn’t decorate your new office with personal items. A gallon of milk has a longer shelf life than a Suns coach these days.

Johnson is the third coach to be fired in the last seven years. This from an organization that once bragged about its stability but now takes cues from the Los Angeles Clippers.

In their hastily called press conference Wednesday — how convenient that the Suns waited until their players had left America West Arena — the Colangelos repeated many of the same lines they used upon the firings of Paul Westphal and Scott Skiles.

Circumstances dictated a change.

We didn’t like the body language. We don’t blame (stick coach’s name in here), but we’re not satisfied with our record. Suckers buy the rhetoric as evidence of the Colangelos’ desire to win. In truth, the firings are desperate acts by desperate men.

Have the Suns underachieved this season? Absolutely. As head coach, Johnson bears some of that responsibility.

But Johnson wasn’t responsible for the $86 million lavished on Penny Hardaway, the $58 million spent on Tom Gugliotta, the preseason trade of Bo Outlaw and Jake Tsakalidis to Memphis to save luxury tax dollars — a deal the Suns tried to correct by acquiring Jahidi White — or the injuries to Amare Stoudemire and Zarko Cabarkapa.

Funny, though, accountability never seems to stop at Bryan Colangelo’s desk. Wonder why.

Don’t count on D’Antoni — who had a 14-36 record as head coach of the Denver Nuggets in 1998-99 — turning the Suns around.

But even if he does, Johnson didn’t deserve such shabby treatment. Last year, in his first full season as coach, he led the Suns to a 44-38 record — the fourth-best improvement among NBA clubs — and a surprising playoff appearance.

Now, after 21 games, he’s gone. So much for storing up good will.

Had the Colangelos admitted they made a mistake hiring Johnson — look, he came cheap and he was available; we took the easy way out — I might be more sympathetic to their position.

But they never turn their criticism on themselves. It’s always the coach’s fault. Westphal couldn’t control his players. Skiles had too much control over his players. Johnson didn’t have the players’ respect.

What hypocrisy. The Colangelos promote young, inexperienced assistants — who presumably need time to grow into the job — then turn on them when things go wrong.