Doc Rivers is coaching Game 3 of the Eastern Conference Finals with a heavy heart.

Orlando Woolridge, who gained a reputation as a rough and tough player throughout his 13-year NBA career, died late Thursday at the age of 52, which hit home for the Celtics head coach.

Woolridge — who suited up for the Bulls, Nets, Lakers, Nuggets, Pistons, Bucks and Sixers in his career — died while under hospice care for a chronic heart condition, according to DeSoto Parish chief deputy coroner Billy Locke.

Rivers discussed Wooldridge's passing before Friday's Game 3.

"That's sad, that really is," Rivers said. "I knew him very well, especially in his Bulls days in Chicago, I got to know him pretty well. It shocked me."

Check out the video above to hear more from Rivers.