The Boston Celtics didn't have enough to defeat the Eastern Conference-leading Philadelphia 76ers on Friday night, and head coach Brad Stevens wasn't the least bit happy.

The Celtics lost 122-110 in Philly, and coach Stevens was upset specifically with regard to their effort on the defensive side of the floor.

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Defense wins championships, and Brad Stevens knows that more than anybody.

Jaylen Brown had 42 points on 16-28 from the field and Marcus Smart and Kemba Walker also finished in double-figures, but the defense was severely lacking.

Joel Embiid continued his impressive season with 38 points on 11-15 from the field and 11 rebounds, and Tobias Harris followed suit with 23 points and 8 boards on 10-12 from the field.

Seth Curry and Ben Simmons each contributed 15 points and the Sixers shot 55 percent from the field on Friday night and had a 42-point third quarter.

The Celtics were in the game late, but Stevens didn't seem too thrilled about some of the possessions in the fourth quarter.

With the Sixers and Brooklyn Nets potentially facing the Celtics come playoff time, the lack of defensive intensity could create issues for Boston. Stevens is one of the best coaches in the league, and playing defense- especially late in games- could be the difference between a Finals trip or not.

Perhaps the imminent return of Jayson Tatum will help this group on the defensive end, but either way, something has to be done if the Celtics want to compete down the stretch.