Does Joel Embiid suit up for the 76ers in Game 1 of their series with the Celtics? The star big man for Philadelphia is suffering from a sprained knee.

The Philadelphia 76ers easily defeated the Brooklyn Nets to advance to the NBA Playoffs’ second round, but the challenge only gets harder from here. Not just because they’re playing the Boston Celtics, either.

In Game 3 of the first-round sweep, star center Joel Embiid strained his LCL. In regards to his chances of playing, head coach Doc Rivers was open and listed him as doubtful over the weekend after he missed Game 4.

Embiid’s status was still officially listed as doubtful on Monday morning, but it was clarified further on Monday night.

The 76ers officially listed Embiid as out for Game 1 an hour and a half before tip off.

That’s definitely a blow to Philadephia’s chances, though Celtics head coach Joe Mazzulla himself was quick to point out that the 76ers are 12-5 this season with Embiid out, per Jay King of The Athletic.

One of those 12 victories was the decisive Game 4 victory over the Nets with Tobias Harris putting up 25 points and 12 rebounds while James Harden had 17 points and 11 assists. DeAnthony Melton came up with 15 points off the bench.

The 76ers will likely deploy a smaller lineup, looking to take advantage of speed matchups and spacing the floor.