The Philadelphia 76ers didn’t know how many games, if any, they could count on from Joel Embiid in their first-round playoff series against the Boston Celtics. After debuting in Game 4 following appendectomy surgery last month, the former MVP played some of the best playoff basketball of his career over the final four games of the series to lead the 76ers to a 109-100 Game 7 victory over a Celtics team that had looked like a potential NBA title contender. The No. 7 seed’s reward is an Eastern Conference semifinals matchup with the No. 3 seed New York Knicks that begins Monday.