Del Mastro is an imposing defender with great size and slightly above average skating/mobility. His stride is a bit unorthodox but his mobility is not hindered too much by it. He plays a very smothering, physical game down low in his zone. He defends the rush well as he has a very good active stick and gap control, he stays up on the play and doesn’t give up his blue line easily. Down low he defends very well, good positioning and uses his size well to tie up or box out his man in front. Can make skilled passes in tight areas and his ability to evade pressure is only going to improve, but he needs to make better decisions on a consistent basis. As a 16-year-old defenseman in the OHL he played big minutes in a more shutdown and PK role, it will be interesting to see if he can improve upon his offensive game and puck moving abilities as he grows as a player.