The Celtics were missing two-fifths of their starting lineup Friday as they looked to snap their first losing streak of the season.

Boston ruled out center Kristaps Porzingis (left ankle sprain) and guard Jrue Holiday (right shoulder impingement) for its matchup with the Indiana Pacers at TD Garden. Both players initially were listed as questionable.

The Pacers were without Obi Toppin (ankle), Andrew Nembhard (knee) and Aaron Nesmith (ankle) on the second night of a back-to-back.

Porzingis suffered his injury during the Celtics’ Christmas Day loss to the Philadelphia 76ers. He tweaked his ankle early in the game, played 13 minutes in the first half and did not emerge from the locker room after halftime.

It was the third injury the 7-foot-2 big man sustained since returning from offseason leg surgery on Nov. 25. The first two (an ankle tweak and a heel bruise) proved minor and did not cause him to miss time. The severity of his latest ailment was unclear as of Friday evening.

“He’s had a couple of them, but he manages his body pretty well,” Celtics head coach Joe Mazzulla said in his pregame news conference. “He’s just got to continue to take care of it. He does a good job of that. I don’t think it’s impacted him too much and hope to get him back soon.”

It was the second consecutive DNP and fifth of the season for Holiday. It’s unclear whether his shoulder issue has contributed to his dip in 3-point shooting percentage, which is down more than 10 points from last season (42.9% to 32.6%).

The 2024-25 Celtics have yet to play a full game with all eight of their core rotation players (Jayson Tatum, Jaylen Brown, Derrick White, Holiday, Porzingis, Al Horford, Payton Pritchard and Sam Hauser) available. That group has missed a combined 48 games this season.

Those absences have created playing-time opportunities for the back half of Boston’s bench, with players like Neemias Queta, Jordan Walsh, Drew Peterson, Baylor Scheierman and Jaden Springer joining Mazzulla’s rotation on select nights.

“I think that a huge key is developing not only your bench, but your bench identity to where (they are) being ready to play at any time, being ready versus a certain matchup,” Mazzulla said. “You get into a situation where one guy may be a perfect fit for a playoff series, and the next, it may be somebody completely different.

“And so building the habits and the things that go into developing different guys for different identities I think is really important over the course of a season, because you don’t get to pick your opponent. You don’t get to pick your matchup. You don’t get to pick the strengths and weaknesses of who your opponent is, and you have to be ready to face those on. So I enjoy those moments. I obviously want to be fully healthy as long as we can, but the times that we’re not, it’s preparing us for the unknowns of the rest of the season and the playoffs.”

Boston entered Friday with a 3-4 record over its last seven games.