By Matt Audilet Doc Rivers has revealed a concerning update on Joel Embiid’s thumb injury. When asked directly if Embiid suffered a ligament tear, the 76ers head coach said “It’s not a good injury. I’ll leave it at that,” per Philadelphia insider Keith Pompey of the Philadelphia Inquirer. Despite this concerning update from Rivers, Embiid reportedly plans to take the court for Saturday’s Game 4 matchup against the Toronto Raptors. He wore a soft cast on his right thumb during the second half of Wednesday’s Game 3 victory, and again during practice on Friday. Embiid is reportedly experiencing “…