The 54-year-old star of "The Green Mile" went into full cardiac arrest early Friday morning and was revived when his girlfriend, reality TV personality Omarosa Stallworth, performed CPR on him.
TMZ said doctors are optimistic about Duncan's recovery because his heartbeat is strong, but have no immediate plans to take him off the respirator.
Duncan has appeared in dozens of films, including "Armageddon," "The Whole Nine Yards" and "Sin City," which all starred Bruce Willis. He also is a popular voice actor who works in animation.
Celebrity Breakups and divorces of 2014 [PHOTOS]