In what appears to be a standoff to prevent a drastic roster overhaul, Boston Celtics coach Doc Rivers seemingly has pushed all of his chips to the center of the table and challenged president of basketball operations Danny Ainge to call his bluff. What happens next could leave the Celtics looking radically different moving forward. For much of the past five weeks, Boston fans have been able to dismiss the idea of Rivers walking away as overhyped speculation. His indecision easily could be chalked up to a coach who has readily admitted to being "pretty much unlivable" during the season and annually needs an offseason detox to rekindle his desire. May be time for a change. That's what a source told ESPN that Rivers believes as he remains publicly noncommittal about spending a 10th season on the Boston bench.