LOS ANGELES -- Celtics coach Doc Rivers is not immune to what goes on outside the Celtics’ circle and he said Thursday morning that he learned of close friend Avery Johnson’s firing the night before. The Brooklyn Nets fired Johnson as their coach after 10 losses in the past 13 games, including a 93-76 pasting by the Celtics on Christmas Day.

”It’s awful,” Rivers said. “Obviously it’s the business we’re in. But it’s a tough one. He’s one of my best friends. It comes out of nowhere. Avery’s a terrific coach, so who knows?”