Nobody is happier about Kevin Garnett's dominant displays in the playoffs than Celtics' head coach Doc Rivers, but for general manager Danny Ainge, Garnett is making his life a lot more difficult ahead of the off-season.

Ainge is the man responsible for the franchise's future as they look to begin the next chapter in their history after the era of the Big Three.

It's fairly common knowledge at this stage that the Celtics are looking to create a younger corp to guide their roster as Ray Allen, Paul Pierce and Garnett enter the twilight of their respective careers. Paul Pierce is expected to finish out his career with the Celtics as he is under contract past this season and will complete a historic one club career if he doesn't play elsewhere.

There is a lot less certainty surrounding the futures of Ray Allen and Kevin Garnett however. Both players are free agents after this season and both are closer to retirement than Pierce. Allen will be 37 years of age come the start of next season while Garnett will be a 36 year old forward.

Despite being a year older, the likelihood that Allen returns to the team this off-season has always been there throughout the regular season and playoffs. Allen's seemingly supernatural fitness and his ability to score without attacking the basket means that his body has a lot less wear and tear than Garnett's or Pierce's.

Also Allen's acceptance of his role as the team's sixth man after the emergence of Avery Bradley paved a way for him to be back next year in a reduced role, on a reduced deal.

Allen is the type of player who will value winning over money at this point in his career, in fact he likely has throughout his whole career. He should have plenty of opportunities to sign elsewhere this off-season but if he thinks the Celtics can contend for a championship, he likely will be back in Boston.

With only a $10 million cap hit on top of everything else working in his favor, Allen makes more financial sense also as Kevin Garnett is coming off a year in which he earned $21 million.

Money won't be the determining factor in whether Garnett returns or not. Garnett has shown through this off-season that he is still a more than capable basketball player despite being 35 years of age but what Garnett needs to understand moving forward is his limitations.

The Celtics have ridden Garnett this year because of their problems in the back court after losing so many forwards to injury, Jermaine O'Neal and Jeff Green most notably. However that is not something they can expect to do as Garnett ages even more.

If Garnett is to return to the Celtics, he will have to understand that he will no longer be the center piece of the team. Garnett would be a prominent player, he may even start, but he would be a role player as the Celtics look to breath life into their roster with youth and potential.

The only certainty on Garnett's future is that he will definitely not be returning to the team for $21 million next year. He has excelled in a makeshift center role but that clearly is not something that is viable for the long-term.

Much like Allen, I suspect Garnett will value victories over money when deciding on his future next year but he also must consider his own passion. Garnett's passion is what makes him great. His competitive nature makes him such a great teammate and dominant defender.

While he is a great teammate, that same passion also makes him desperate to be on the court as much as possible.

Danny Ainge must decide what is a reasonable investment in Garnett this off-season. Prior to his performances in the playoffs it would have been relatively easy for the Celtics general manager to simply cut ties with Garnett, move on and use the cap space to reinvest in multiple pieces which carried more potential.

Ainge is in a difficult, but undoubtedly more preferable, position.