Ray Allen went to Doc Rivers and told him it was time. At this point in his career and with this team specifically, it was time to move to the bench and begin a new chapter in his career.

According to Rivers, this conversation took place before Avery Bradley suddenly morphed into a game-changing defensive killer with an effective offensive game. The idea was to move Mickael Pietrus into the starting lineup where his defensive versatility would allow them to switch more on the perimeter and form a potentially devastating combination with Rajon Rondo in the backcourt.

Then Pietrus suffered a severe, Grade III concussion against Philadelphia and Bradley got his chance. Regardless of who is starting opposite Rondo, and whether Rivers ultimately changes the lineup again, Allen’s unselfish move has helped open a new set of possibilities for the Celtics as they move from one era to the next.

Call it: The transition plan.

With limited options in free agency, would it make sense for the Celtics to bring back both Kevin Garnett and Allen now that both players have accepted playing different roles and reset the expiring contract clock?

This is just one possibility, but it’s an option that has gained traction since the All-Star break. Garnett has been rejuvenated playing center and team president Danny Ainge has found keepers in Pietrus, Bradley and Brandon Bass to name three. If Allen were willing to come back as a reserve and they were able to re-sign everyone they wanted to sign including Jeff Green, Ainge retain a very good team while stockpiling assets for a future deal.

To be clear, Ainge and his staff don’t know exactly what they’re going to do when the season ends. They have eight players who will become unrestricted free agents in addition to Bass who has a player option. A number of different things can happen depending on factors that are well as out of their control.

The one thing they do now is that there is no quick-fix. They won’t have a chance to draft Kentucky’s Anthony Davis and with Dwight Howard and Chris Paul removing themselves from the free agent market by agreeing to waive their early termination options, there are no franchise players available. In fact, there are very few good options available in free agency, at all. (There are, however, a number of intriguing restricted free agent possibilities, and we’ll address those next week.)

So, let’s say the Celtics decide to bide their time while the next wave of great players become available. It will be at least a two or three-year timeframe before the likes of James Harden, Blake Griffin and Kevin Love can hit free agency, or possibly be on the trade market. Rather than sliding idly into the lottery and hoping to get lucky in the draft, the Celtics can maintain a competitive team and still keep their long-term options open.

It might look something like this:

PG: Rajon Rondo
SG: Mickael Pietrus
SF: Paul Pierce
PF: Brandon Bass
C: Kevin Garnett
Rotation players: Avery Bradley, Ray Allen, Jeff Green, Greg Stiemsma
Developing players: E’Twaun Moore, JaJuan Johnson, two first round picks

Re-signing those veterans would almost certainly take the Celtics over the salary cap line (estimated to be about $58 million), but if they were able to stay under the luxury tax line, they would be able enjoy greater trade flexibility as well as mechanisms like the room exception, that allows for a player to sign for $2.5 million. (The tax line is the real key under the new collective bargaining agreement.) A roster like that could also give Ainge trade assets in the form of short-term contracts and prospects.

This is just one of many options that Ainge could utilize, but it’s one that wasn’t even realistic until the team began playing better and veterans like Garnett and Allen made uncomfortable moves at key points in their careers.

The new lineup

One of the reasons for the Allen switch was to get a tougher defensive group on the floor at the start of games. The lineup with Bradley and the other four starters is a staggering 24 points better than the opposition and holding teams to just 87 points per 100 possessions. The Allen lineup barely breaks even.

It’s not just about Allen, however. Rivers believes that Bradley and Pietrus also have a positive effect on Rajon Rondo.

“They’re such tough defenders and they give you a disposition,” Rivers said. “We’ve already got Kevin on the floor and I think with Avery and Pietrus they give Rondo life defensively. He feels like, I’ve got some guys out here that can put pressure on the ball.”

The key word is pressure. Rondo’s steals are down this season, but the Celtics still rank sixth overall in forcing turnovers. That comes from constant ball pressure that forces teams into mistakes, rather than forcing the action with gambles.

“We’ve done a good job of getting into the ball, keeping the ball in front of us, not going for steals,” Keyon Dooling said. “Ironically, our defense is so good, if you don’t got for steals with our defense you can still get turnovers and you can get out in transition.”

Rondo has steered clear of questions asking if he has a preference in a backcourt partner, but he did note after the Spurs game that, “I think we’re a lot faster. With the guards on the court, they can get down with you and spread the floor.”

Locker room chemistry

After conducting an actual practice last week, Garnett stayed after to work with Ryan Hollins on a variety of things. The impromptu tutorial runs counter to the perception that Garnett is a bloodless meanie.

“He does it with the guys he likes,” Rivers said. “He’s clearly taking a liking to [Hollins]. He loves how verbal he is in practice. He thinks he has chance to be a great pick and roll defender. Kevin, every new guy he gives you about two or three chances and if you listen and follow he’ll teach you every day. If he thinks you’re disinterested that’s probably the last lesson you’ll get and that’s probably the best lesson you’ll get in some ways too. He’s a terrific teacher. I kid him and tell him he’d be a great coach but I don’t know if I’d want any of that as a player.”

The Celtics locker room is a tough place. The veterans – particularly Garnett, Rondo and Paul Pierce – will test you constantly to see what you’re made of and it’s not just the young players who feel their sharp edge.

Earlier this season, Bass noted that things got easier for him once he discovered that he could give it right back to them. But the young players have stood out this season for their maturity and professionalism and the veterans have taken note.

“He’s like a little sponge,” Dooling said of Bradley. “He sits around and just listens to all the wisdom that’s in this locker room and he does it humbly, quietly, but you feel his presence when he’s on the court.”

The Celtics are not the most fun-loving group. They don’t do viral videos or impromptu comedy bits, but they do enjoy a professional working atmosphere and Rivers believes that has been instrumental in persevering through a difficult season.

“Our locker room is good. It’s terrific,” Rivers said. “Avery, E’Twaun and JaJuan, it’s just a good, refreshing locker room. It really is. It’s a fun group when you go to practice, when you’re on a bus or a plane with them, you just like being with them and this year that may correlate into wins. This is a hard year. It really helps when you like being around guys.”

Rondo and the spotlight

Here’s Rondo on his reputation for playing his best when the bright lights of national television are shining: 

“I don’t know what it is,” Rondo said after dropping a triple double on the Heat in the Celtics’ most impressive victory of the season. “I think my teammates put the spotlight on me more than the media and the televised games.”

So Rondo pulls a disappearing act from time to time in the middle of the winter. That’s not good, mind you, and looks even worse when he has the ball in his hands and the responsibility for keeping the sputtering engine that is the Celtics’ offense from turning into a clunking lemon. If he could play at his best every night we wouldn’t be having an argument over whether he deserved to be in the top-whatever of point guards.

However, he’s been here for six years and it’s pretty clear that this is who he is. Rondo’s not perfect, but if he’s going to pick and choose his spots with his slashing style, shouldn’t it be in the big games?