Irving is reportedly dealing with a left knee contusion. He reportedly worked out before the game but later decided he could not play. The 22-year-old reportedly injured the knee in the Cavaliers' Christmas Day loss to the Heat in Miami.
Over 28 games this season, Irving has averaged 20.2 points, 5.3 assists and 1.5 steals while posting a 19.8 Player Efficiency Rating. With Irving out, backup Matthew Dellavedova (3.3 ppg, 2.5 apg) is expected to start.
The Cavaliers had won three consecutive games prior to the loss to Miami. Irving scored 25 points on 10-of-19 shooting over 42 minutes. Cleveland enters Friday's game in Orlando at 17-11, good for fifth place in the Eastern Conference.