Celtics injury updates: Marcus Smart upgraded to probable, Al Horford doubtful for Game 2 vs. Heat | CBS Sports Headlines Celtics injury updates: Marcus Smart upgraded to probable, Al Horford doubtful for Game 2 vs. Heat Smart has a sprained right foot, and Horford is in health and safety protocols … Continue reading Celtics injury updates: Marcus Smart upgraded to probable, Al Horford doubtful for Game 2 vs. Heat