By the end, Celtic followers had come to believe in their team enough to realize that Game 7 against the Cavaliers was a bad loss. They understood fully what the Celts still had even without Kyrie Irving and Gordon Hayward, and they knew that, while success in the NBA Finals was out of reach, these guys were good enough to get there.

But the belief of those outside the dressing room was largely immaterial to getting the Celtics to last call in the conference finals. So when did the players begin to think a deep run was realistic?

It’s not so obvious a question. The C’s had their psyche hit hard when they lost Hayward a few minutes into the season opener. They had come into the season expecting to be in The Finals, and if they could get their act together along the way, perhaps they’d even have a shot against the Warriors (there was no doubt among anyone really that Golden State would be waiting).

But even after they appeared to get over the Hayward hit and were more than competitive against the league’s elite, Irving went down for the season. He was in and out with knee pain, then played his last game on March 11.

When the C’s learned he needed surgery and was done, it’s fair to say there was more than a little uncertainty.

“When we lost Kyrie, we were trying to figure out how it was going to go,” said Marcus Morris. “Then Jaylen (Brown) went down for a little while, but we still kept winning.

“I think that’s when people realized we were good, and our confidence just soared from there. It was more like, ‘Hey, we don’t have nothing to lose at this point.’ ”

The C’s lost by two to the Pacers when Irving played 16 minutes in his last game, and they fell by one at home to Washington a few days later and split a two-game trip to Orlando and New Orleans.

Then they won six in a row, with home wins over Oklahoma City and Toronto bookending a four-game road sweep of Portland, Sacramento, Phoenix and Utah.

“Once we kept getting wins anyway — once we saw how good we still were — that gave us hope,” said Terry Rozier. “We just built off of that. When we started winning even without those guys, we just kept building. We kept getting better.

“We started realizing we had each other, and that’s all that matters.”

When the postseason arrived, Marcus Morris believed the way the chips fell was advantageous to the Celts. While most believed they’d have trouble with the Bucks — and they did, needing seven games to advance — and they were a decided underdog against the 76ers, the C’s felt otherwise.

“I think when it really clicked again was when we saw the draw of the playoffs — when we got Milwaukee and Philly,” Morris said. “We were kind of like, that works in our favor. We knew we matched up with those teams pretty well.

“I always thought we were better than Philly. So we just took off and kept going.”

But while most of the Celtics began to see the possibilities, Marcus Smart kept the blinders on.

Asked if there was a point he came to know that the run was realistic, he said, “Not while it was happening. And the reason I say that is the simple fact that we were playing at an incredible rate as a team, and that dream is what keeps you going in a certain way. You know, not knowing that it’s real, just kind of living in that life and that dream world. It’s that world where anything’s possible, and we kept that mentality. We went out there and it translated onto the court for us.”

The Celtics tried to stay in the moment — until the moment caught up with them. They got rushed when the Cavs came back on them last Sunday night, and they shot themselves out of a wide-open opportunity to make The Finals.

But Smart was still proud of how the Celts avoided the crutch of the missing stars. To think about how different things would be with Irving and Hayward would have been counterproductive.

“You definitely have to block it out,” Smart said. “That’s part of being a professional. You know, things happen. Adversity happens. But it ain’t about how hard it is. We’ve all heard the cliche that it’s not about how hard you get knocked down, it’s about what you do after you get knocked down. You know, how quick you get back up.

“So, yeah, we got been knocked down a few times throughout the season, but every time we did, we got back up.”

Except this last time when they knocked themselves down and there were no more games to play . . . until next season.