The Oklahoma City Thunder will be without their franchise player for Tuesday's home game against the Boston Celtics after Shai Gilgeous-Alexander was ruled out due to an illness.

Gilgeous-Alexander, 24, is in the midst of a breakout season that has him the favourite for the Most Improved Player award.

After averaging 24.5 points per game this past season on shooting splits of 45/30/81, the Canadian has jumped up to 30.8 points per game on 49/35/91 to sit fifth in scoring.

Almost a lock for his first All-Star appearance this season, Gilgeous-Alexander has helped his relatively mediocre Thunder team to a 10-9 home record, although they are 5-12 on the road, leaving them with the sixth-worst record in the league at 15-21.

On the flip-side, the Celtics own the league's best record at 26-11, and the league's best offense, scoring 117.2 points per 100 possessions. Meanwhile, the Thunder are way down with the 24th-ranked offense (110.5) despite Gilgeous-Alexander playing all but three games.