The Celtics are entering a pivotal time in their rebuilding plan. Team president Danny Ainge worked feverishly the past two years to accumulate draft picks, trade exceptions, and salary cap space to create flexibility to procure a couple of difference-making players in coming years.

What we do know is everybody isn’t coming back. As much as the Celtics faithful appreciated the efforts of those players who made an improbable playoff run, there are going to have to be some dramatic changes to upgrade the roster.


What the playoffs did, however briefly, was potentially separate the keepers from those who are expendable. Ainge didn’t design this team to make the postseason. He designed the roster to have players who could learn under Stevens, and to be salary friendly to allow more transactions this summer.

What we found out is that Jae Crowder is a keeper. The rugged swingman proved his value throughout the regular season after being acquired from the Mavericks in the Rajon Rondo trade in December. Crowder flourished in the playoff series against LeBron James and the Cavaliers before being injured after being hit by J.R. Smith in Game 4.

The Celtics were fortunate to learn Crowder only sprained his left anterior cruciate ligament after crumbling to the floor and he should be ready for training camp. Crowder is a restricted free agent, meaning the Celtics have the right to match any offer from other clubs, and that should be a certainty.

Quite honestly, the Celtics lack toughness, especially in the paint. What Crowder brings to their arsenal is a physical player who can defend scoring small forwards. While his success against James was uneven, he at least provided some resistance against the league’s best. Crowder has to stay.


As for Jared Sullinger, he made amends after being injury prone yet again during the season, averaging 12.3 points and seven rebounds in the Cleveland series, including a 21-point, 11-rebound outing in Game 4.

Sullinger’s situation is interesting. He is eligible for a long-term extension this summer. But his agent, David Falk, told the Globe in February he generally does not agree to contract extensions that aren’t maximum, which begins at approximately $15 million per season. The Celtics aren’t going to offer that. They want to see if Sullinger can work himself into premium shape and put full concentration and emphasis on improvement this summer.

And if the Celtics have their eyes focused on an impact players such as Kevin Love — if he can be convinced to come to Boston — do they attempt to trade Sullinger this summer? That may not be the most astute move. Sullinger is only 23 and has averaged 11.4 points and 7.4 rebounds in his career.

If the Celtics do trade Sullinger, they would have to replace him with an upgrade. Other than that, he stays.

Kelly Olynyk was maddeningly inconsistent during his second season and then made headlines for all the wrong reasons for his actions in Game 4. The Celtics envisioned Olynyk as a stretch four who could use his skills as a former point guard to get into the paint. But what they found is that Olynyk, at times, lacks toughness and confidence.


Olynyk is going to need to get stronger during the summer and approach his game with more seriousness and aggression. But at this point, he seems expendable. The Celtics realize they may have to sacrifice some of their younger players to get more talented and experienced.

With the 16th and 28th picks, the Celtics could add two more younger players to their equation, but don’t expect Ainge to keep both of those picks. Eventually the Celtics will have to acquire veterans. Filling the roster with a slew of rookies and hoping they develop into a winner generally doesn’t work. Just ask the Sacramento Kings.

A wild card here is rookie James Young, who was taken 17th in the 2014 draft and spent most of his first season in the NBADL. The Celtics need a scorer, a swingman who can shoot from the perimeter, take defenders off the dribble, and get to the free throw line. What was rather frustrating about Young’s injury riddled rookie season is that the Celtics weren’t able to determine much about his future except that he has potential.

So does the organization sign a difference-making small forward who may just be a few years older than Young or allow Young to develop and perhaps flourish in an increased role next season? Ainge said he had full faith that Young would develop into a contributor, but if the Celtics are looking to make a major leap next season, do they wait on him?


As much as the Celtics have enjoyed the contributions of Brandon Bass and Gerald Wallace, it may be time to allow Bass to leave via free agency and find a taker for the final year of Wallace’s contract ($10.1 million).

Although Stevens truly liked his roster, he refused to say he was content or pleased with this season’s results. He will be on the phone July 1 to recruit newcomers, and the roster could be dramatically different next season.

“I’m not a big salesman, never have been, not been very good at it,” said Stevens. “The only thing I can ever say is: you want to be part of a great environment. It’s a good environment. That makes the whole experience better. And for me, that’s our task: to continue to build and grow within that environment. Because we’ve got a good foundation and culture moving forward.”

Related coverage:

■ Celtics forward Kelly Olynyk sorry Cavs’ Kevin Love was injured

■ Dupont: Celtics face an important offseason

Gary Washburn can be reached at gwashburn@globe.com. Follow him on Twitter @GwashburnGlobe.