INDIANAPOLIS – Al Horford has been in this situation before.

It was during the 2016-17 season, his first with Boston. The Celtics concluded that regular season with the Eastern Conference’s best record before losing to the Cleveland Cavaliers in the conference finals.

Yet as Horford can attest, that team overcame some rough spots that season. One such stretch was when it lost five of eight games during a stretch from mid-February through early March.

The Celtics also had three separate three-game losing streaks before then.

“The one thing over there, we continued to play," Horford said. "We continued to figure things out and get better.

“So I guess that’s my message to the [Sixers] group. It’s like we need to stick together.”

Philly’s season has been a roller coaster, and now it’s on the low side. The Sixers are 23-13, but are looking to snap their third three-game losing streak of the season, have lost six of their last nine games, and are 7-11 on the road.

Things could get worse before they get better for one of the preseason favorites to reach the NBA Finals.

The Sixers travel to the 23-11 Houston Rockets on Friday before hosting the 18-15 Oklahoma City Thunder on Monday and the 23-8 Celtics on Jan. 9. Then they’ll have road games at the 21-12 Dallas Mavericks on Jan. 11 and the 22-12 Indiana Pacers on Jan. 13.

But Horford believes sticking together will enable to the Sixers to persevere.

"We have to be more conscious of doing the things that coach wants us to do, defensively,” he said. “We have to be better. There’s just a lot of breakdowns.

“If we continue to stay the course, I think we will be fine. I think we will be able to break through it.”

That’s what happened during the 2016-17 season when the Celtics turned things around.

“It really, really picked up at the end of the year,” he said. “It’s hard right now because we are living through it. But we’re close.”

Right now, the Sixers are making too many mental mistakes and missing assignments on defense. Those miscues were largely responsible for their current skid, which includes road losses to the Orlando Magic on Friday, the Miami Heat on Saturday, and the Pacers on Tuesday.

However, they limited the mental mistakes and missed assignments in their Christmas Day victory over the visiting Milwaukee Bucks.

“So that’s our mentality,” Horford said. “We have to understand we have to bring that same focus every time.”