The Brazil defender spoke to Efe after yesterday's 3-2 defeat of Everton.
Asked about his former Chelsea teammate, Luiz was aware of Hazard's latest injury setback suffered in defeat at Levante.
He insisted: "It is not worrying, because it can happen to anyone in football. I am sad for him because I know the player he is and the person he is.
"He has not yet had the opportunity to have the continuity of playing and showing the level he has."
Asked whether he will recover and succeed with Real, Luiz was clear: "No doubt he will."