The first free agent decision came before the official start of free agency when it was reported that Kevin Garnett will not retire, instead signing a three-year, $34 million contract to remain with the Boston Celtics.

A source told the Boston Herald that once Garnett decided he was going to continue playing, the Celtics were the only option. That makes sense because has a strong relationship with Doc Rivers, as well as many of the players and is still a perfect fit with the team.

Bringing back Garnett means the Celtics aren’t going to endure a significant transformation this summer, unless they unexpectedly field trade offers for Paul Pierce or Rajon Rondo. This is significant because as recently as a few days ago, there was some doubt as to whether Garnett would return (regardless of what Bill Simmons claims).

Boston could still lose Ray Allen in free agency, but with all due respect to the NBA’s all-time leader in three-point field goals made, he doesn’t mean nearly as much to this team as Garnett does.

Here are the reasons why the three-year agreement was good for the Celtics and some rationale as to why it might be bad:

He’s the embodiment of the team

Pierce is the captain (his place in Boston lore is greater because he’s never known another team) and Rondo is the best player, but Garnett is the embodiment of the Celtics. You can close your eyes and see him playing alongside legends like Havlicek, Bird and McHale and not looking out of place. There aren’t metrics out there that can quantify the impact Garnett has made in the locker room and on the floor since he arrived from Minnesota.

Since joining forces to form the original Big Three, Pierce and Allen have both bought into playing tougher on the defensive end. Pierce, one of the most despised players outside of his own market, has earned a tremendous amount of respect over the last five years because he has become more controlled on the court.

Garnett and Pierce are still known for flashes of emotion, unlike the stoic Allen, but the constant look of ‘I’ve been wronged’ is no longer permanently splashed across Pierce's face. That isn’t something Garnett would allow.

And let’s be honest, the Celtics had no business coming within a victory of reaching the NBA Finals this spring. They entered the postseason as the fifth seed in a top-heavy conference and as recently as early February, there were calls for a trade deadline makeover. Thanks to Garnett, who came to tolerate and excel at center, not his natural position or something he initially enjoyed, the Celtics were hot enough in the second half of the regular season to avoid playing a heavyweight in the first round.

They didn’t dominate the Hawks or 76ers by any means, but they got the eight wins needed to face Miami in the Conference Finals and had two chances to eliminate LeBron James yet again. It wasn’t meant to be, but that playoff run wouldn’t have been at all without Garnett.

His presence makes selling easier

The Celtics are a title contender on the downturn, but playing with a guy like Garnett is still a nice selling point. Young players in the league, including some just coming off their rookie contracts, don’t remember an NBA without KG. That’s more important than you might think. They have also seen what playing with him does to your career.

Their sports, playing styles and personalities are vastly different, but Garnett compares to Derek Jeter in many ways as an elite athlete. 

Both players leave it all out on the playing surface, work harder than others without bragging about the hours they put in and support their coaches (at least publicly) without hesitation.

If you put on a Yankee uniform and take the field, you’d better give 110%. Jeter doesn’t have to give you a look -- although he might -- because his mere presence forces others to be on watch. You give for the team, not for yourself.

Over the last five years, Garnett has entered that realm. You can see it as any member of the Celtics dives on the floor for a loose ball. You can see it when Rondo, who was in just his second-year when Garnett arrived, puts his body on the line in an inconsequential regular season game. You can also see it when Rondo does military-style push-ups just a few days after Garnett first broke them out. Younger players want be like him, while also pleasing him.

With Garnett still in the fold, free agents both this summer and next will know the Celtics mean business and that a complete meltdown is impossible.

Shortening the learning curve

Jared Sullinger and Fab Melo are the two newest members of the Celtics, having been selected with back-to-back picks in the first round of Thursday night’s NBA Draft. When news broke on Saturday that Garnett would be returning, Sullinger and Melo saw their futures become that much brighter.

Garnett’s approach with young big men isn’t always completely hands-on, but look at some of the young bigs that have learned from him and eventually succeeded at the professional level.

Kendrick Perkins was the weak link in the starting five to begin Garnett’s first season with the Celtics. Fast forward a little more than two years later and Perkins is one of the best interior defenders and rebounders in the game and his absence in Game 7 of the 2010 NBA Finals can be pointed to as a reason why Boston didn't win their second title in three years.

Glen Davis arrived to the Celtics in the same summer as Garnett and learned not to be intimidated on the court. He’s still known as “Big Baby” but has some manlike qualities to his game now. If it weren’t for his toughness and midrange jumpers in the first round for Orlando against Indiana, what was a five-game series would have been a sweep.

Sullinger and Melo could be the next Perkins and Davis, learning the NBA ropes under Garnett before coming into their own as professionals. If that’s the case, the Celtics could benefit just as much as the two rookies.

With that said, the pair have to be willing to work and sacrifice, otherwise Garnett won’t have time to waste on helping them along.

He’s back and the title window may remain open

Let’s assume the Celtics re-sign Brandon Bass, Mickael Pietrus and Jeff Green, who is expected to return to the court without trouble following a heart condition.

They then throw the rest of their salary cap space at Ray Allen, but he leaves anyway. That money is used to sign a three-point threat, a backup for Rondo that is more dynamic than Keyon Dooling (no disrespect to the Reverend) and/or a center that can start some games.

How is that team, with a starting lineup of Rondo-Avery Bradley-Pierce-Bass-Garnett not at least as good as the 2011-12 squad?

Bradley is another year older and although I have misgivings about him as an 82-game starter, less is asked of him because Pietrus has better knees and Green is ready to deliver on some of the promise he carried when he arrived from Oklahoma City.

There has to be concern about Garnett and/or Pierce breaking down physically, but they have shown an ability to play through pain and manage their bodies well enough to remain on the court. You also have to remember that next season is going to be a lot less rigorous than this past one. It’ll be 16 more games played over an additional two months.

The Eastern Conference is also primed to be a bit weaker.

The Bulls will be without Rose for a least half of the season, the Pacers have welcomed a new front office regime and both Roy Hibbert and George Hill are restricted free agents and Dwight Howard trade rumors will last with Orlando until he’s either dealt.

You could also surmise that Garnett’s return makes re-signing Allen a little more probable. Allen may not be content coming off the bench behind Bradley or have a great relationship with Rondo, but aside from Miami (his main suitor) there aren’t really any better situations.

The Celtics can provide Allen with familiarity, a playoff run, more money than anyone else, close proximity to where he has some roots (he played college ball at UConn) and his children. His son, Walker, has had issues with juvenile diabetes and has spent time in local hospitals, and his daughter, Tierra, plays volleyball at Quinnipiac University.

Delaying the inevitable

Unless Ainge overhauls the supporting cast by getting veterans to sign for cheaper than market value, it will take a certain amount of luck and good fortune for the Celtics to sniff the NBA Finals next June.

Pierce and Garnett will be a year older, there isn’t a guarantee that Bradley can play 36 minutes over 82 games and have the same effect and signing Garnett to a three-year deal might hamstring the franchise for longer than necessary.

In re-signing Garnett, Ainge confirms that he still sees the team as a championship contender because spending money to remain competitive with KG will lengthen the team’s transformation to the next era. Ainge need look no further west than Indianapolis to see how long a makeover takes when a team doesn’t hit rock bottom.

The Pacers were never high enough in the lottery to grab a top pick and accelerate their rebuilding process, so they had to develop the players they drafted in the middle of the order and hope they didn’t swing-and-miss. Of course, Indiana isn’t a large market nor does the franchise have the history the Celtics do (no one does), but Ainge will have to work harder in trade talks and free-agent negotiations if the team isn’t going to accept a few bad seasons in exchange for a high pick.

Some of the guess work in the drafting process can be avoided too, as Ainge knows all too well. He traded the fifth overall pick to Seattle in exchange for Allen back in 2007. The Celtics didn’t use that high pick, but it still helped them hasten the evolution from doormat to championship team. In fact, Ainge used it to engineer the most drastic turnaround in NBA history. They went from 24 wins to 62 and a ring in one year.

What will come of the contract?

You have to ask yourself -- how does someone have one foot into retirement and than decide to play basketball for another three years?

When the Nets were linked to Garnett a few months ago, I wondered whether he would use Brooklyn as leverage in talks with Boston, or vice versa. I’m now wondering if Garnett used retirement as a bargaining tool.

The Celtics wanted Garnett back bad enough to give a 36-year-old power forward with high mileage a three-year contract worth an average of $11.33 million. Most NBA contracts escalate in value, so one could assume that Garnett’s could look something like this: $10.5 million (2012-13), $11.5 million (2013-14) and $12 million (2014-15).

While Garnett continues to regress, his contract will become more cumbersome to a team now pushing a three-year plan with the Big Three to years six, seven and eight.

Unless Garnett finds the foundation of youth and the Celtics win a championship in one of the next two seasons, it is almost certain that his contract will become a trade chip around the deadline in 2015. He’ll either be a fit for a contending team if Boston has regressed that severely or provide salary cap relief for someone as Ainge looks to be proactive.

That may seem sensible at this point, but three Februarys from now it will be a harder split. Signing Garnett to a two-, or even one-, year deal would have allowed Boston to undergo a clean divorce. Whether Ainge offered Garnett three years or he conceded to his demands, he made the end much more arduous.

The consensus

This free agent class wasn’t suited for the Celtics, who could have had ample money to spend if they allowed Garnett (and Allen) to walk.

The truth is that at 36, Garnett is still highly effective. He had the highest defensive rating in the league last season, anchoring one of the best units in basketball. He can still hit a midrange jumper with the best of them and when sufficiently motivated and fired up (ahem, Michael Gearon, ahem) he can outrebound guys that were in diapers when he entered the league.

The Celtics will be better with Garnett next season than they would have been without him, and that’s sometimes more than enough in today's NBA.