BOSTON -- The Celtics have just eight games remaining in their regular season.

Perhaps they need someone to tell them that.

After dropping their fourth game in a row -- losing 115-96 to the San Antonio Spurs at TD Garden on Sunday night -- Boston is now two full games behind the Indiana Pacers for home court in the first round of the Eastern Conference playoffs, and remains mired in the same cycle of inconsistency that has dogged the Celtics all season long.

Rather than being concerned about it, though, the Celtics remain convinced -- or, at minimum, are projecting an air of confidence -- that, when the playoffs begin, they will be just fine.

"We got a lot of guys back, and we're all trying to figure out exactly what everybody's favorite things to do and what spots that everybody excels at and make sure we get everybody in the right position," Celtics guard Marcus Smart said. "We're still fooling with it. But I see great progress, and I'm excited, I'm ecstatic, and I'm happy with what we're doing.

"Yeah, we've been losing, and it's been frustrating, but that's the beauty of this game. We get to go play another one and we get another chance to go out there and work on things we need to work on."

It'd be one thing if that was the attitude permeating Boston's locker room in October. Even in January. But it's now the last week of March; the start of the playoffs is less than three weeks away. Celtics coach Brad Stevens took almost 20 minutes to leave the locker room postgame, and it wasn't opened for 40.

For months, the Celtics have been carrying themselves with a mindset similar to that of the Golden State Warriors, in that the regular season is nothing more than a meaningless 82-game tuneup for the postseason.

The difference is that Golden State has four future Hall of Famers in its starting lineup, and is coming off four straight NBA Finals appearances and three championships in the past four seasons. Boston, meanwhile, has only one player on its roster -- Al Horford -- who was even in the NBA the last time the Celtics made the NBA Finals.

Of course, Boston has another player -- Kyrie Irving -- who has plenty of postseason experience, including hitting one of the biggest shots in NBA history to win the 2016 NBA Finals for the Cleveland Cavaliers over those Warriors. And, as he has for months now, Irving reiterated after Sunday's game that these games have no meaning to him.

"Oh, it's not hard," Irving said, when asked if it is hard to remain patient through the team's recent struggles. "I'm used to gearing up for something bigger than myself around this time, and what it takes, and I have to do a better job of communicating that to my teammates and being a better listener and kind of figuring out how to best communicate with those guys that point.

"At this point of the season, I'm on the VersaClimber, I'm on the treadmill, I'm getting ready to play 40-plus minutes and getting ready for the wars and battles. At the end of the season, it's just practice time. You don't feel right about your jump shot, you don't feel right about the team. ... We're still developing as a team.

"It's been a whole season doing so, but there's light at the end of all this. That's probably where my patience will always lie, is knowing that something's beyond this. This challenge is happening for a reason, and I've got to believe in that."

The Celtics have been the NBA's most confounding team this season. Even after this four-game losing streak, Boston remains tied for ninth in the NBA in offensive efficiency, and fifth in defensive efficiency. Being in the top 10 in both offense and defense is considered one of the trademark qualities of a true championship contender.

Boston was certainly supposed to be one this season. And, as those numbers prove, there is some statistical evidence to back that up. But even Stevens said last week that the numbers don't match up with the eye test. And anyone who watched the Celtics lollygag their way through Sunday's loss to San Antonio -- one in which LaMarcus Aldridge torched Boston's defense for 48 points -- would be hard-pressed to think otherwise.

"We have to be better," Stevens said. "We were a better defensive team in the first two months of the season than we've played at any time in the last month. So, to me, it's not about what we're doing. It's about how well we do it every single night.

"That's where we have to get back to. And so, we're getting exposed by good teams."

There was something fitting about the Spurs being Sunday night's opponent for the Celtics. San Antonio was left for dead after trading Kawhi Leonard last summer, and losing promising young guard Dejounte Murray before the season began to a knee injury. Yet, despite that, the Spurs continue to execute coach Gregg Popovich's system and play hard on a nightly basis.

That has allowed the Spurs, despite their talent deficiencies, to reach the postseason for the 22nd straight season.

"I am," Popovich said, when asked if he's having fun this season. "The challenge is great, and this is actually one of the more enjoyable seasons, because it's been fun to watch Bryn Forbes develop and Davis Bertans and Derrick White and so forth.

"It's satisfying."

There has been nothing satisfying, however, about this Celtics season. Boston entered the season expected to finish atop the Eastern Conference standings because of an abundance of talent. Instead, with eight games to go, the Celtics will likely have to win three straight series without home-court advantage to do so.

Yet, despite their season-long issues, they remain confident that, once the playoffs arrive, they will be able to right the ship.

"I don't think that's what it is," Smart told ESPN when asked if he thought the Celtics were waiting for the playoffs to flip a switch and fix things. "I think it's that we're so talented, that we're not stressing like everybody else is, because we know once we do get it clicking -- once we get that, we feel like we will be back to ourselves.

"We're not as worried because we are so talented, and everything going on right now can, and will, be fixed."