Kevin Garnett's return means another run for a championship for the Celtics.
The Celtics should be a little over $40 million in salary with the cap at $58 million after the deal and will have the flexibility to add complementary pieces to the rest of the lineup.
Whether or not all the pieces of the Big Four return is yet to be, Boston is once again a legitimate championship contender.
With Celtics fans hoping for and even expecting a possible championship run for the sixth straight season, President Danny Ainge should spare no expense to finding the right core of players to work alongside Garnett, Paul Pierce and Rajon Rondo.
Here are the five moves Ainge needs to make this offseason after learning that KG will be back.
O.J. Mayo is a very coveted player, especially by the Celtics.
According to Yahoo! Sports, Ray Allen was nearly traded by Boston in order to get O.J. Mayo, so we know the Celtics are interested in his services.
Now that he is an unrestricted free agent and has shown well in a sixth-man role with the Memphis Grizzlies the last two years, Boston needs to pursue him. He can play both guard positions, and since Paul Pierce is turning 35 they need someone who can create their own shot.
Mayo is not as deadly a three-point shooter as Ray Allen, but he did shoot 36% on three-point shots last season. He is extremely durable, only having missed eleven games in his entire career.
If they can add him for anywhere from $8 to $10 million, Boston should make a big run at him with full-court press by veteran Celtics. He is a player who provides an instant scoring punch of the bench.
Chris Kaman could help extend KG's Career, which will only open Boston's championship window wider.
With Chris Kaman the only legitimate starting center in unrestricted free agency, the Celtics need to at least entertain the idea in order to have Kevin Garnett play his natural position of power forward.
When Garnett and Kendrick Perkins were healthy together for a full year, Boston was the toughest and best team in basketball. They had the most versatility in the post of any team in the league since KG can play as an undersized center.
Kaman is a skilled seven-footer who can still score in the post and is only 30, so the Celtics can use the Lakers' model of having two towering players inside to defend the painted area and also set picks offensively.
Kevin Garnett is much better as an occasional center in an uptempo lineup.
Adding Kaman would make a lot more sense than bringing back Brandon Bass since he is undersized, and Jared Sullinger was just drafted.
The additions of Kaman and Mayo will give the Celtics a solid six players to lead their team and then there is hopefully some cap space and the mid-level exception for other pieces.
Josh Howard is only 32 and may have two to three years left as a bench player.
With Paul Pierce playing big minutes through injuries in the postseason, his offensive performance took a huge dip, and he even fouled out three times in a span of five games.
To get the best 35 minutes a game from him, there needs to be a clear backup small forward who provides a good offensive and defensive game.
That could be anyone from Jeff Green to Josh Howard to Tracy McGrady to even Grant Hill.
With Hill, McGrady and Howard aging, joining up with Boston may be their best opportunity to win an NBA Championship.
Whatever direction they go, the extra depth will be extremely important for Boston.
Michael Pietrus was an integral part of Boston's rotation in the postseason.
With O.J. Mayo able to play some point guard and no clear backup shooting guard when Mayo plays some point, Michael Pietrus should be brought back.
He is a veteran sharpshooter who plays with great intensity on both sides and recovered from an ugly concussion to contribute greatly to a phenomenal run by Boston last year.
Though he will be a smaller piece next season if the first three moves occur, Pietrus will have his best chance to win a title in that role and maybe cash in the next offseason.
Dooling is not a true point guard, but he stretches the floor with his three-point shooting and is a veteran player who isn't afraid to take a big shot.
The more players who can stretch the floor and have ice water in their veins for the Celtics, the better their chance for a championship this season.
Ray Allen could join Shane Battier in Miami.
With the NBA champion Miami Heat ready to make a big run at Ray Allen, according to ESPN's Brian Windhorst (Pro Basketball Talk), unless Boston is able to use their mid-level exception on Allen, or if he takes a smaller deal with the Celtics, it may be time to let this one of the Big Four go.
Allen didn't start for much of the second half of the season with Avery Bradley's presence and missed twenty games during the regular season.
His 45% three-point shooting aside, Allen's shooting percentage dropped from .491 to .458. With Mayo providing the same type of skills plus ball handling and more durability, Ray could be on the outside looking in as of now.
That being said, if he wants to come back to Boston, you can't see how the two sides don't make it happen.
But Boston shouldn't guarantee him a clear rotation spot either as a starter or sixth man due to the presence of Bradley and potential presence of Mayo.