 Complete the following phrase:  Later in the season, on December 18, the Celtics released yet another player, Brandon Wallace, in order to have even more roster flexibility that coach Doc Rivers said they needed. This move brought the roster down to only 13 players, which is the league minimum for players allowed on a teams roster. On February 27, the Celtics signed center P.J. Brown for the remainder of the season, in order to bolster their front court. His decision to come to Boston was strongly aided by a conversation with future teammates Ray Allen and Paul Pierce, who convinced him to sign with the Celtics during the 