Kevin Garnett has a decision to make, and that decision will likely determine in which direction the Boston Celtics choose to go this summer. Will he return for another year, or will he retire?

Surprisingly, it seems as if Garnett's eventual announcement will be the first domino to fall for the Celtics. If KG wants to come back for another season, then Boston will probably opt to bring the team back for another run.

If not, general manager Danny Ainge will almost certainly begin the rebuilding process.

You would think that the Celtics' decision on Paul Pierce would be the main factor in the path Ainge selects, as Pierce's $15 million salary for 2013-14 becomes guaranteed on July 1. If the Celtics waive him prior to that date, they would only be on the hook for $5 million. They could also trade him, in which case his contract would no longer be their problem.

As outlined by Steve Bulpett of the Boston Herald, the C's are still waiting on a decision from Garnett. Doc Rivers is undecided on his future, too, but logic dictates that he is more than likely holding off until he knows what is going on with KG.

All of this leads me to believe that, as coy as Ainge has been about everything, the Celtics are willing to take another shot with this core group as long as Garnett wants to do the same. So, if KG says he is returning, chances are you will see Boston hang on to Pierce and then try to bolster the roster through trades and free agency.

Judging from the fact that the departure of the two veterans would only open up a small amount of cap space, that may be the best way to go.

It makes sense, too, as it is hard to envision Garnett wanting to come back without Pierce in tow.

What some don't realize is that KG and Pierce have a history that dates long before their days as C's teammates. They have been friends since they were 13 years old, and Garnett has acknowledged that Pierce was one of the main reasons why he accepted the trade to the Celtics during the summer of 2007.

Throughout the six years that KG has been in Boston, Pierce has been right there with him. They have won a championship and have been to two NBA Finals together. They have experienced it all, and at 37 years of age, it doesn't seem likely that Garnett would choose to return to the C's if Pierce isn't part of the package.

Why would he? Better yet, why should he?

KG has already accomplished everything a professional basketball player could dream of, winning a title, collecting Most Valuable Player and Defensive Player of the Year awards, making countless All-NBA teams and being elected to 15 All-Star games. Other than achieving some statistical milestones, what's left?

Given the fact that he was hobbled during the 2013 playoffs, playing with a hip pointer and bone spurs in both ankles, it seems fairly safe to conclude that Garnett will not be taking the floor for what would be his 18th season unless he knows he has a shot at another ring. In order for that opportunity to present itself, Pierce will probably have to be in green come the fall.

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Of course, KG could always just tell the Celtics to trade him to a contender if Aingepulls the plug on Pierce, but do you really think that is going to happen? It's hard to imagine Garnett finishing his career anywhere else. After all, if that were even an option in his mind, don't you think he would have announced that he is returning already?

The future Hall of Famer has two years and about $24 million remaining on his deal. That's a lot of money to leave on the table. Based on that, if KG had any intention of potentially changing addresses, it probably wouldn't be taking him this long to make a decision. It's either Boston or retirement.

Garnett's contract may as well have a clause that states the pact is only valid if Pierce's presence is guaranteed. He and The Truth are like brothers.

Consider this.

KG is the same age as Tim Duncan, whose San Antonio Spurs are currently engaged in a finals battle with the Miami Heat. Manu Ginobili, a part of the Spurs' own Big Three, is 35, the same age as Pierce. Then you have Tony Parker, four years older than Rajon Rondo.

Garnett is probably looking at San Antonio and thinking, "Why can't that be us? If they can do it, we certainly can."

Duncan's trip to the finals is almost certainly being monitored by Garnett. 
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And you know what? With the right moves in the offseason, the C's probably can. Obviously, a whole lot of things would have to go "right" this summer for that to have a chance of occurring, but one has to assume that KG is watching the Spurs with that mindset.

That's why Garnett is only going to come back if Pierce is in a Celtics uniform. San Antonio has given Boston hope, hope that, in KG's mind, is only legitimate if The Truth's leash is extended for another season.