BOSTON – The Boston Celtics understand that the path to Banner 18 is not an easy trek. There are bumps along the way, but that’s all part of the process they must endure as they strive for their ultimate goal.

Boston hit one of those bumps Thursday night when it was eliminated from the Playoffs by the Cleveland Cavaliers. Naturally, the players had sour tastes in their mouths following the season-ending, 135-102 loss in Game 5 of the Eastern Conference Finals.

It’s a taste that will likely stick with the Celtics for the next few months, but coach Brad Stevens stresses to them that it will only get sweeter from there.

“I told our guys, ‘We made a lot of great strides,’ ” Stevens relayed to the media following Thursday’s game. “ ‘But this pain is part of the path to what we ultimately want to be.’ ”

Boston began its journey four summers ago when it overhauled its roster by cutting ties with veteran legends in order to pave the way for the future. A lengthy rebuild was anticipated, but the Celtics have exceeded expectations with their rapid growth over the last four seasons under Stevens.

The first year of the rebuild was the toughest. The C’s finished near the bottom of the standings during the 2013-14 season and missed the Playoffs for the first time in seven years.

From there, things have only trended upward in Boston.

The Celtics snuck into the 2015 Playoffs as the East's seventh seed, then earned the fifth seed the following postseason, and finally rose all the way up to the No. 1 seed this postseason and made a run to the Eastern Conference Finals.

While Boston was unable to dethrone the defending NBA champions, Avery Bradley believes that the series against Cleveland served as a vital stepping-stone for the C’s.

“The great thing about this is the experience,” said Bradley, who has been with Boston throughout its rebuild. “We were able to go to the Eastern Conference Finals, learn a lot about being in this position, and I feel like it's going to help us for next year.”

Next year, the C’s should only be better. They will make the No. 1 pick in the draft, they will have the opportunity to bolster their roster in free agency, and their young, talented core will continue to develop along the way.

“The sky's the limit for this team if we're able to keep together core guys and add some new pieces,” said Bradley. “I feel like (president of basketball operations) Danny Ainge and our entire organization do a great job of putting the right guys together to help us be a contender for a championship.”

The key to contending is having a relentless, yearlong approach. Stevens describes it as a “holistic commitment.”

“It's the way you eat, it's the way you sleep, it's the way you treat your body in the offseason, it's how hard you work at the little things you need to do better,” said the coach. “But more importantly, it's what you do best, and perfecting those things.”

The Celtics will take a few weeks off to recover and collect themselves, but then it’s back to work. Stevens is counting on his players to grind through the summer so that they’re ready to take one step further next season on their quest to Banner 18.

“When they come back, the expectation is everybody is a little bit better,” said Stevens. “And that goes for me and the rest of the coaches, too. I don't think anybody in there is satisfied, which is a good thing.”

The only thing that would satisfy the Celtics is winning it all. They know they have a lot of work to do to reach that goal. They understand that there may still be a few bumps on the road ahead. But when they trip over those bumps, the C’s will get back up, brush off their wounds and continue along their way.

Pain is just part of the path.

Sour will soon turn into sweetness.