It’s not a rivalry.

Joel Embiid has made sure to say it loudly so that everyone knows that the 76ers have yet to play up to the level of the Boston Celtics, at least during his tenure with the team.

“I don’t know our record against them, but it’s pretty bad," he said following the Sixers' opening-night loss in Boston on Oct. 16. "They always kick our [butts].”

The Sixers have a 2-15 record against the Celtics since Embiid has been in the NBA, so it’s no wonder that he was bitter about how things ended in their opening-night contest when the Celtics whipped the Philadelphia squad, 105-87. Certainly no one has forgotten the second-round playoff series from last season when the Celtics sent the Sixers packing after just five games.

Once again, the Sixers will enter TD Garden, this time on Christmas Day, to play in a nationally televised game, against a Celtics team that has had their number for years.

The Celtics, who have struggled to find their identity this season, will be without Aron Baynes, and Al Horford has just returned from injury. But Sixers coach Brett Brown knows Boston will be ready.

“I still see Kyrie [Irving] and [Gordon] Hayward and [Jayson] Tatum and [Jaylen] Brown, and it’s in the Boston Garden, and it’s Christmas,” he said. “It’s a big game.”

The Sixers enter Tuesday’s game with a 22-12 record, tied for third place in the Eastern Conference with the Indiana Pacers and just ahead of the Celtics (19-13).

This Sixers team isn’t the same one that was in Boston to kick off the 2018-19 season. This time, they come equipped with Jimmy Butler and they hope they can start a five-game road trip with a gift on Christmas Day.

Though the Sixers have Butler, they also have a thin bench that has been inconsistent through this season and will have a tough task of keeping up with the Celtics. But the Celtics haven’t had the easiest road this season, either.

A 10-10 start to the season forced the Celtics to re-evaluate their approach. Hayward is still finding his footing after a gruesome injury cost him the 2017-18 season. Rotations have changed with Hayward coming off the bench, and injuries have impacted retooled lineups. Additionally, Tatum and Brown have had trouble living up to their inspiring performances in the 2018 playoffs.

The Celtics woes culminated in a closed-door team meeting after a loss to the Milwaukee Bucks on Friday. They responded to the frustrating loss with a 119-103 win over the Charlotte Hornets on Sunday and will be looking to build on that momentum when they meet the Sixers.

Though the Sixers haven’t had the the same kind of internal strife, their season has not been without twists and turns. Wilson Chandler (left quad contusion) is listed as questionable, dealing another blow to the Sixers' depth. Markelle Fultz and Zhaire Smith, whose injury sagas have been as long as they have been mysterious, will be on hand to watch their team play but will be in street clothes.

Despite the Sixers' depth problems, their trouble against elite teams, and their struggle to handle opposing guards, they have managed to stay in the top tier of the East. Embiid continues to make his case for MVP this season, while Ben Simmons, JJ Redick, and Butler help to round out one of the best and most feared starting units in the NBA.

The Celtics have been able to stop the Sixers at nearly every turn, and Tuesday’s outcome won’t change history. But a Sixers win on Christmas Day could do wonders in giving the Philadelphia team the confidence that it could start to stem the tide.