The Celtics have recalled Fab Melo from the Red Claws. Melo missed the Red Claws New Years Eve game with a mild concussion. The last time Melo was called up to the Celtics it was for treatment for an injury and my guess is that it's the same for this call up. According to reports, he sustained the concussion by hitting his head walking through a door. No, I'm not joking.
A week ago Doc said that he didn't have any indication that Fab was ready for NBA level play and I haven't heard him say differently. So my guess is that, as with his last call up, Fab is with the team for evaluation and treatment for his concussion. The Celtics sure could use a rim protector, though. Just saying.