If you’re not contending, then you’re rebuilding.

Many front office execs in sports accept this maxim as an article of faith. Once the championship window closes for a team, the theory goes, it’s best to blow things up, particularly in basketball, where a salary cap generally prevents a team from adding high-dollar talent to bolster an imperfect roster. Whereas the Yankees and Red Sox can erase personnel mistakes by signing a couple of All-Stars, NBA organizations don’t have that kind of flexibility — not in the last collective bargaining agreement and certainly not in the next one.

But rebuilding is painful, and like many painful exercises, it’s prone to procrastination. We tend to put off breakups, hernia surgeries, spring cleanings and bankruptcies. Denial isn’t always the factor that fuels this holding pattern. We consciously know these chores need to be tackled, however unpleasant they might be, and rebuilding is no different.

The Phoenix Suns are facing this dilemma right now. They’ve historically been one of the league’s most competitive teams season in and season out. Every fall, fans in Maricopa County know that if they plop down the cash for season tickets, they’re almost guaranteed to see more wins than losses, an exciting brand of basketball and a decent chance the Suns will play games well into May.

These are vital ingredients to the Suns brand, and just a few reasons why Phoenix remains one of the few three-sport cities in North America where the NBA is king. Even as the Suns have shipped off draft picks like Rajon Rondo and Luol Deng, they’ve maintained their standing as a franchise many fans in rival cities would gladly trade for their own. Fourteen months ago, they played a spirited Western Conference finals series against the eventual NBA champion Los Angeles Lakers.

So when you talk about rebuilding in Phoenix, it’s a very serious matter, even though the Suns’ 40-42 record last season suggests that their demise is inevitable. The primary reason why that conversation is so grave is the presence of 37-year-old point guard Steve Nash.

Provided we have a 2011-12 NBA season, Nash will enter the final season of his contract with the Suns. Once Nash is off the books next summer, Phoenix will have only $28.26 million in salaries committed heading into the 2012-13. The recipient of those guaranteed contracts are Marcin Gortat, Josh Childress, Channing Frye, Jared Dudley and Hakim Warrick. Dudley is the youngest of the five — none of whom qualify as foundational players on a contender — and he’ll be 27 years old on opening night 2012.

Yet, the Suns will have flexibility — but only if they say goodbye to Nash next summer. The two-time MVP has been the most important face of the 43-year-old franchise and that farewell won’t be easy and isn’t necessarily inevitable.

Michael Schwartz of Valley of the Suns takes a hard look at the implications of both parting with Nash and extending him a new contract. He sees three possible scenarios:

1. Trade Nash immediately after the lockout or at the trade deadline.

2. Sign Nash to a two-year extension.

3. Let Nash walk at the end of the 2011-12 season.

Each of these possibilities is fraught with peril. Re-sign a player who will be 40 years old at the end of the contract and there’s a likelihood you won’t see a good return on your investment and just delaying that needed surgery.

But if the Suns let Nash walk, there’s no guarantee that cap space will translate into an impact signing — and now you’re forced to fill out a roster with marginal players. We often forget that future success isn’t a foregone conclusion when a team moves forward with a teardown. Sometimes that lot sits barren for years. Kevin Durant and Derrick Rose don’t always land on the doorstep.

Two more seasons of Nash might stall the rebuilding process, but it probably means the Suns remain watchable and they’ll also be treated to the warm fuzzies a franchise enjoys when it sends off a legend with a farewell tour. In addition, Nash appears to have some game left in the tank. His Player Efficiency Rating (PER) was fifth-best among point guards and he elevates the offensive performance of his teammates.

Nash’s presence would be very nice salve to a 37-45 season — though mediocrity for Phoenix has its drawbacks. A win total in that neighborhood means the Suns will likely be drafting somewhere in the 10-15 range, limiting their chances of landing a future All-Star.

For the Suns and their fans, this is a tortuous thought process with few attractive options. And that’s why our closets and garages fill up with old stuff even though we know damn well it’s time to purge.