The Boston Celtics have given up 49 offensive rebounds in three preseason games. They’ve struggled to limit opposing teams to single-shot possessions. In the last two outings, head coach Joe Mazzulla has resorted to immediately pulling players off the floor if they miss a defensive board or fail to box out. Mazzulla is clearly sending a message to his young and primarily unproven roster: Defensive rebounding is a non-negotiable under his leadership. Unfortunately for Boston and Mazzulla, they don’t have a wealth of defensive rebounding talent at their disposal. During a Sunday postgame news conference following the Celtics’ 138-107 win over a depleted Cleveland Cavaliers roster, Mazzulla explained how his primary goal right now is to find a five-man lineup capable of securing the defensive glass. “Five guys on the floor, everyone is responsible for rebounding,” Mazzulla said. “…Everybody knows if it’s a 50/50 loose ball, you go get it. …Will, technique, whatever you gotta do, you do it.” Last season, Jay
