The Vegas Golden Knights currently have only $1,200,000 in cap space. While they have Mark Stone with a $9,500,000 million cap hit and
Alec Martinez, one of their top defensemen, with a $5,250,000 million cap hit, on Long Term Injured Reserve. That means to activate one of these players, Vegas would need to move someone to LTIR or trade away a roster player for essentially nothing to make the cap space work.