Both Matulino and Mason are wearing the brunt of the NRL's promise to crack down on the shoulder charge.
Last Friday's NRL announcement that any shoulder charge "with force" would now draw a charge was intended to improve player safety and remove ambiguity, but it left questions unanswered - including what level of contact constitutes "force".
The latest crackdown came amid controversy four days after Sydney Roosters prop Kane Evans escaped MRC punishment for a massive hit which decked Canterbury's Sam Kasiano.
The loss of Matulino comes as another blow to the injury hit 10th placed Warriors, who are battling to keep their slim finals hopes alive following four consecutive defeats to the Roosters, Sea Eagles, Sharks and Dragons.
The Warriors are set to name their side tonight for Saturday's vital clash against the Penrith Panthers at Pepper Stadium and are also unlikely to have veteran winger Manu Vatuvei in their line-up.
The 29-year-old was forced from the field with a recurrence of an injury to his right shoulder 60 minutes into Saturday's defeat at Westpac Stadium in Wellington.
The latest setback comes after he was sidelined for three games in July after initially sustaining the injury in the June 27 match against the Canberra Raiders, before he returned to action against the Sharks on August 1.
The full extent of the injury is still being assessed but Vatuvei is rated a doubtful starter this weekend.
He joins Ryan Hoffman (calf), Bodene Thompson (ankle) and David Fusitu'a (knee) who are all still on the injured list. That trio are all hopeful of being available for selection either for this weekend's match or for the following game against the North Queensland Cowboys at Mt Smart Stadium.