Irving enjoyed a strong debut season with the Celtics after he was acquired via trade from the Cleveland Cavaliers last August. He averaged 24.4 points, 5.1 assists and 3.8 rebounds per game while shooting 49.1 percent from the field, including 40.8 percent from three-point range, across 60 games in 2017-18.
The 26-year-old Duke product's season ended in March, and he underwent two knee procedures. Injuries have plagued him throughout his career, as he has missed at least seven games in every season and played in fewer than 60 contests three times in six years with the Cavs.
If he's forced into another stint on the sideline, Terry Rozier figures to receive the lion's share of the playing time at the point. It would also lead to an uptick in minutes for Marcus Smart, who serves as the top reserve at both guard spots.
All told, Irving is one of the NBA's top players when healthy, as he illustrated last year by ranking ninth in player efficiency rating, per ESPN.com. A long-term absence would be a significant setback for Boston despite its depth.