After going 56-26 in the regular season and earning the No. 2 seed in the NBA playoffs, the Boston Celtics saw their season end in shocking fashion on Saturday night as they dropped a 109-100 contest against the Philadelphia 76ers at TD Garden.

The Celtics had a 3-1 series lead before losing three straight games, culminating in the Game 7 defeat.

The Celtics are now 15-8 against the 76ers in 23 total playoff series. They had won the previous six playoff series.

Here's what you need to know.

Jayson Tatum played more limited minutes in Game 6 of the series, but the assumption was that it was because of the lopsided score and not the calf issue he was nursing on the bench.

Head coach Joe Mazzulla told the media that Tatum would play on Friday, but he was downgraded to questionable on Saturday afternoon and eventually ruled out. Despite the apparent calf issue, he was ruled out with left knee stifness. 

Though the Celtics had 66 games of regular season experience without Tatum, it's never advantageous to be without one of your best players.

In addition to Tatum's absence, Mazzulla shook up the starting lineup, benching Sam Hauser and Neemias Queta in favor of Baylor Scheireman, Luka Garza and Ron Harper Jr.

Garza played only nine minutes while Harper played just four. None of the new starters scored in the game.

--Jaylen Brown had a team-high 33 points for Boston, and he was 12-of-27 from the floor.

--Derrick White still struggled with his shooting efficiency, but he did have 26 points. He was just 9-of-26 from the floor. 

--Queta (17), Payton Pritchard (13) and Hauser (11) each scored in double figures.

--Though he didn't score, Hugo Gonzalez provided some nice minutes, playing 13.

--On the other side, Joel Embiid scored a game-high 34 points while Tyrese Maxey had 30 points on 11-of-18 shooting. VJ Edgecombe had 23 and Paul George had 13.

--The Celtics were just 13-of-47 from three-point range. As the saying goes "live by the three, die by the three."

Embiid missed the first three games of this series, and even though the Celtics won big in his return in Game 4, the 76ers clearly unlocked something when he returned. Embiid scored 19 points or more in each game he played, while scoring 33 or more twice.

A long offseason where they will wonder how they let this opportunity slip away. We will have plenty more at Celtics Roundtable, evaluating the state of the roster and the organization.

For now, it's just the realization that the season is over and the championship dreams are no more.

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