Celtics' Al Horford: Ruled out for Wednesday

Horford (concussion) has been ruled out for Wednesday's game against the Mavericks, Celtics play-by-play announcer Sean Grande reports.

Analysis:

Despite being a participant in Tuesday's light practice, Horford is still not symptom-free and will have to miss his eighth straight game. He looks to be trending in the right direction, however, and his next opportunity to return will be Friday against the Warriors. Kelly Olynyk will once again start in Horford's place on Wednesday.