 A versatile and well-rounded midfielder, De Napoli was usually deployed as either a central or defensive midfielder, where he was capable of both supporting his more creative teammates defensively, and of functioning as a deep-lying playmaker after winning back possession, courtesy of his range of passing, and ability to build plays and create chances from midfield with long balls; he was also deployed on the wing on occasion.A quick, hard-working, and tenacious player, with good technique, he was known in particular for his notable stamina, as well as his excellent man-marking ability, which endowed him with the ability to break down the opposition's play, and subsequently transition the ball from defence to attack; he also possessed a powerful and accurate shot from distance, and was known for his ability to make attacking runs and charge forward with the ball from deeper areas of the pitch.His tenacity and combative playing style earned him the nickname "Rambo" from the Napoli fans throughout his career.