Celtics' Al Horford: Full participant in light practice

Horford (concussion) participated in practice Tuesday and is questionable to play Wednesday against the Mavericks.

Analysis:

The Celtics only went through a light practice Tuesday, so Horford's participation may not mean as much as it usually would, but it's still a positive sign for the big man, who's missed the last seven games with a concussion. Horford looked to be in good spirits Tuesday, but the team will wait until shootaround Wednesday to evaluate him and decide if he's officially symptom-free. Once Horford is cleared, Kelly Olynyk or Amir Johnson will shift to the bench.