First let me say that I am not a doctor and this is based on research. I know you guys are looking for answers and maybe this will start a dialogue and maybe some of the Celtic's fan on this site can chime in that have more head trauma experience.
I'm praying for Pietrus.
I do fear that the report of a closed head injury along with the live report of him vomiting blood may mean either a brain contusion or a level 3 brain concussion.
A concussion is more likely since we saw there was no impact on the floor. A concussion can still occur without direct impact. Severe whip lash can in fact cause a concussion.
I hope he recovers and doesn't have any permanent brain damage but for those of you concerned with the state of the team it isn't likely he will return this season.
I admit this is based on limited facts at hand but it is an educated guess and I want everyone to be ready for the worst.
I hope I'm wrong and somehow it is a mild concussion.