THE NRL has branded two feet-first tackles by Melbourne fullback Billy Slater in the Grand Final as dangerous and warned he risks suspension if he continues. NRL referees director Robert Finch warned Slater he needed to be "careful". "If he should kick the ball out of a player's hands or make contact with a player's head the repercussions could be grave," Finch said. "It could be a penalty try, an eight-point try, someone could be hurt or a player could be sent off." Slater incensed many spectators in last Sunday's Grand Final by sliding feet-first at two Manly players trying to ground the ball for tries. Click here to purchase great photos from the NRL grand final The two tackles occurred within 10 minutes of each other with Slater sliding towards Manly hooker Matt Ballin in the 23rd minute and then towards left winger Michael Robertson in the 33rd. Yesterday the match review committee pinpointed Slater's tackles - calling the first one "dangerous" and the second "very dangerous". In both incidents the judiciary said referee Tony Archer could have cautioned Slater. Finch said kicking the ball from a player's hands was illegal. "They can strip the ball but they can't kick it."