We’ll learn pretty quick if Phil Jackson is serious about constructing a championship contender at the Garden.

If he re-ups Carmelo or lets him stick around one more season on a player option, it’s a clear sign Phil is here only to cash in on Jim Dolan’s desperation.

If Phil ushers Melo and his expiring contract outta here at season’s end – or does a sign and trade, you know Jax is earnest about this difficult endeavor to restore some order to a franchise in disarray.

I have no clue what’s motivating Jackson to jump into such a horrible mess created largely by an owner famous for fostering toxic operational structures. For Jax, maybe it’s a Larry Brown-like grab-the-dough and go. If that’s what he’s doing, I think it dents his 11-ring coaching legacy. I strongly disagree with Harvey Araton’s contention in the Sunday paper that this is a no-lose prop for the Zen Master.

Wrote Harvey: “If things do not go well and Jackson’s celebrity fades in Dolan’s easily jaded eyes, the inevitable war will break out, chaos will ensue, and history tells us that most of the blame, in the final analysis, will fall on Dolan.”

Yeah, but a coach who has so carefully calibrated his career moves will be scrutinized intensely given the understanding he’s getting unprecedented autonomy from MSG. If Jackson doesn’t make the Knicks better – and flounders without fight or effort – he risks tainting his nearly unblemished body of work.

I trust Phil’s vision of team-building will start with the removal of a maxed-out player contract failing to gain consistently maxed-out effort in return, especially on the defensive end. If Melo gets a new deal, it’ll be Phil who makes that call. And it’ll be clear then that it’s about the cash – not the Zen.