Philadelphia 76ers center Joel Embiid has been sidelined indefinitely after undergoing surgery for appendicitis in Houston.The procedure took place on Thursday, coinciding with a scheduled matchup against the Houston Rockets.The team announced the diagnosis following Embiid's withdrawal from recent play due to what was initially described as a general illness.While the 76ers have not provided a specific timeline for his return, recovery from an appendectomy typically sidelines professional athletes for approximately three weeks.