The defending-champion Boston Celtics were nearly flawless in the playoffs last season, but this year is a different story. They're down 3-1 to the New York Knicks in the Eastern Conference Semifinals and lost superstar Jayson Tatum to a ruptured right Achilles in Game 4.

The Boston Celtics experienced how quickly the momentum can shift in the NBA Playoffs. After beating the New York Knicks 115-93 in Game 3, they lost 121-113 on Monday and lost superstar Jayson Tatum to a leg injury.

The somber atmosphere was about much more than the team falling down 3-1 in their series against the Knicks. Instead, the concern was centered around All-Star Jayson Tatum, who left the game in the fourth quarter with what appeared to be a serious right leg injury.