Philadelphia 76ers star Joel Embiid sat out of Monday night's game against the league-leading Utah Jazz with back tightness.

Embiid had been listed as questionable for Monday's game during the day, but coach Doc Rivers said he was unaware of any issues with his superstar big man during his pregame media session, telling reporters he expected Embiid to play.

But then, a short time before tip-off, Embiid was ruled out with back tightness. It's been an ongoing source of discomfort for him dating back for a month -- and especially since he took a hard fall against the Los Angeles Lakers in Philadelphia on Jan. 27 when he was fouled by LeBron James.

Embiid is in the middle of the best season of his career, putting himself in the middle of the MVP conversation thanks both to his play and that of the Sixers as a whole, who entered Monday with the best record in the Eastern Conference.

That said, Philadelphia has lost back-to-back games to the Portland Trail Blazers and Phoenix Suns.

Philadelphia is 1-4 when Embiid doesn't play this season, with the lone win coming in Indiana on January 31 and requiring a crazy fourth-quarter comeback to get the Sixers the win.

The Sixers started Mike Scott in Embiid's place on Monday, with Ben Simmons assuming the role of the Sixers' center.