Players were free to report to the Celtics' practice facility for the first time last week, and training camp officially begins on Friday, when coach Doc Rivers (left) will get to work with his new team for the first time since the end of the NBA lockout. How many players he'll have to work with is in question. The Celtics currently have six players under contract. That's not enough to field a scrimmage, and certainly not enough to win a title. A lot will change between now and Dec. 25, when games begin, and between now and June. With that backdrop, we give our best guess at 10 predictions for the upcoming season.