This trade was facilitated to ensure Vegas GM George McPhee stayed away from defencemen Josh Manson and Sami Vatanen, both of whom were left unprotected.
Clayton Stoner was selected by the Golden Knights. The 32-year-old blueliner has one year remaining on his contract with a $3.25-million salary cap hit.
Theodore, 21, suited up for 34 regular-season games and played some of his best hockey in the post-season as he racked up eight points in 14 playoff contests. The 26th-overall pick from the 2013 NHL Draft also impressed during his various stints with the San Diego Gulls in the AHL this past season.