A year ago, Danny Ainge was asked to do something dramatic. His team was flat and looked old, injured and cooked. Instead, Ainge did nothing at the trade deadline except swap Eddie House for Nate Robinson. His faith was rewarded with an unexpected run to the NBA finals.

There were no cries for change this year and relatively few concerns about how the Celtics were faring. Health was again the primary concern, but this team had the best record in the Eastern Conference and had knocked off virtually every top contender in the game.

The C's owned three wins over Miami, two over Orlando and one each against Chicago, San Antonio and the Lakers. There was no need to do anything dramatic. Just fill in a hole behind Paul Pierce at small forward and maybe add a veteran here or there to compete the puzzle.

Ever the maverick, in one bold and unexpected move, Ainge changed the direction of his team for the present and began planning for the future when he traded Kendrick Perkins and Nate Robinson to Oklahoma City for Jeff Green and Nenad Krstic.

Make no mistake, this was a stunner. It’s also a gamble. With Perkins back, the Celtics had their starting five intact that had been so successful over the last 3 1/2 seasons. There was no unknown there. This was the team that everyone acknowledged was the toughest out in the Eastern Conference.

In dealing Perkins, Ainge is risking messing with the twin pillars that have served his team so well: defense and chemistry. There may have been no more together team in the league than the Celtics, and their unique bond was not forged by friendship and good feelings so much as it was built on trust and dependability.

They fought together and just as often with each other, but there was never any real question as to whether they had each other’s backs. Perkins was a key component in their alchemy. He was the muscle behind the strut, and his perpetual scowl served as their public face.

That era suddenly is over now. Perkins is with the Thunder, and the Celtics are going to rely on Shaquille O’Neal and to a lesser extent Jermaine O’Neal to man the middle with Krstic.

While shocking, this didn’t happen overnight. In fact, the whole process began several weeks ago when Marquis Daniels crumpled to the floor in a frightening incident during a game with Orlando. Daniels was carted off the court on a stretcher and it was later revealed that he had been playing with a spinal cord issue. This was the one contingency for which the Celtics had no backup plan, because Daniels was the only capable small forward on the roster who could fill in behind Pierce.

In an interview on WEEI Thursday night, Ainge was asked if he would have made the deal if not for the Daniels injury. He paused for a few seconds. “You know, it’s a good question,” he said. “I felt like our team was playing very well. Once we started looking for those wing players, it did change things a little bit.”

Considering what the Celtics had to offer, the market for small forwards was limited. So Ainge considered something big. Something drastic. Ultimately he pulled the trigger on a deal that will either redefine the Celtics or serve as their epitaph. It was not a move he made lightly.

“It’s not easy at all,” Ainge said. “We agonized over it. Both Doc [Rivers] and I agonized over it back and forth. It was a very, very difficult decision to make, yet one that we thought was best for the team and where we’re headed.”

In adding Green the Celtics believe they have finally found their James Posey, albeit a younger and more athletic version. At 6-foot-9, Green can play both forward spots. He’s not a great rebounder and he’s not the 3-point threat that Posey was, but he’s a better offensive player who could shine in a role as a super-sub.

The Celtics have a history with Green. He was the draft pick that was the main carrot in the trade that brought them Ray Allen, and he played with Rivers’ son Jeremiah at Georgetown.

He is not only backup insurance for Pierce but also a player who can team with Glen Davis in a variety of lineups to counter what had been a traditional team.

Where once the C's were concerned with size above all else to battle the likes of Dwight Howard and the Lakers, Ainge has shifted the focus to length and versatility. The Celtics’ main competitors in the East are now the Heat and Bulls, and its not a coincidence that neither rely on a true center.

The Celtics are now more active and agile, which should play well against the likes of Joakim Noah and Carlos Boozer and LeBron James and Chris Bosh. Ainge indicated he feels that Shaq will be able to make up the difference inside against bigger teams once he returns from his Achilles injury, and he pointed to the team’s success when O’Neal was the starting center.

“Shaq has proven to be excellent with our starters,” Ainge said. “The numbers actually show that he has been better with our starters. We beat all the good teams in the league while Kendrick was out. I did worry about [Shaq] a little coming off the bench. I think he’s more suited to be a starter just because of his age and it takes him a while to get loose.”

And, against all odds and reasoned logic, Ainge remains convinced that Jermaine O’Neal will return at the end of the season and be a contributor in the playoffs. Along with those two there is now Krstic, a 7-footer with range and the added value of decent health.

If the O’Neals can’t come back or if they break down again in the playoffs, Ainge may rue the day he traded Perkins. That’s the risk.

Ainge was not as sold, however, on the well-being of Semih Erden, and he traded him along with Luke Harangody to Cleveland for a second-round draft pick.

“Semih’s been hurt himself and he’s been playing hurt this year," Ainge said. "I’m not sure how much help he would be for us right now. He’s struggling with his health and we really couldn’t count on him to be ready to go as the postseason came on.”

In essence, he traded them for roster spots to sign veterans who will be bought out of their contracts in the coming days. To that end, he also cut ties with Daniels, flipping him to Sacramento, which needed salary to come up to the league’s minimum level.

While it sounds heartless, the move was done in concert with Daniels, who had to sign off on the deal as a player with "Early Bird" protection rights. Reached after the deadline, Daniels’ agent, Mark Bartelstein, said the primary concern was his client’s health and that the basketball considerations were secondary.

These are uncertain and scary times for Daniels, and in agreeing to the move, the team player made one last selfless concession. That opens up three roster spots, and Ainge said that he would be looking for help on the wing and up front. He might add a guard as well, but the other two areas were his top priorities. It would make sense to leave another spot open and be sure Delonte West can handle the load as the backup point guard.

How he fills those gaps will go a long way in determining the Celtics' fortunes for this season. Beyond that, the Perkins trade opens up a world of possibilities that didn’t previously exist.

Perkins is set to be a free agent after this season, and Ainge had offered him an extension. It was the most he could offer under the rules of the current collective bargaining agreement. Unsurprisingly, Perkins turned it down.

“He wanted to test the market,” Ainge said. “Last time, he didn’t test the market, and this time he wanted to see what his value was, and that was a concern. It wasn’t so much of a concern that we would have done something just for that purpose. But the fact we were able, in our opinion, help our team for this year and protect ourselves for the future was very good for us.”

No one knows what the new CBA will look like, but if a hard cap is put into a place — or at least a more restrictive one — teams are going to have to make tough choices on which players to keep. The Celtics made perhaps their toughest decision before their hand was forced. Glen Davis will also be a free agent after this season, and it’s doubtful they could have kept both.

Then there’s the free agent class of 2012, which will feature Dwight Howard, among others. With Perkins gone, Pierce nearing the end and Rondo working under a very favorable deal for a player with his abilities, the Celtics could be big players that summer.

Ultimately though, this season was about winning a championship. All moves were made with an eye on that goal, and the future remained a nebulous cloud of speculation. Ainge is trying to pull off a move that addresses both short-term needs and long-term concerns, and that is no easy task.

“We think it upgrades our team,” Ainge said. “You always have to give up something of value to get something of value in return. We feel this will help our team this year and help us in the future as well.” 

Whether Ainge’s gambit turns out to be recklessly shortsighted or fearlessly brilliant, it was undoubtedly a bold move.