Las Vegas Raiders running back Alexander Mattison (ankle) has officially been ruled out for the team's Week 13 game against the division-rival Kansas City Chiefs on Black Friday. Mattison missed last week's loss to the division-rival Denver Broncos and came into Friday's contest as questionable, but he'll now miss his second straight game. With Zamir White (quadriceps) also missing a second straight game, Ameer Abdullah is in line to make a second straight start, with Sincere McCormick and ...