AZ Sports says they will move Murphy to the slot on nickle and dime packages according to their guys covering the team. I guess that implies he starts as CB on 1st and 2cnd downs.
and not to beat a dead horse, but:
Murphy was literally the teams' highest rated corner last year.
Murphy as a third year player is probably very different from Murphy as a rookie
Murphy in a role as a player in his first or second year doesn't pigeon hole him into that role forever.
Could he fail outside? Sure, but people are treating it as fait accompli based on the first 6 games of his career when forced into the CB1 role.