Marrs completed a move to The Jakemans Stadium on Friday afternoon, following a successful loan spell last season.
The 21-year-old discussed acclimatising to an unfamiliar midfield role in Saturday's 1-1 draw against Stalybridge Celtic.
Marrs wants to put himself in the shop window by delivering solid performances for the Pilgrims, continuing at Bradford Park Avenue on Saturday.
United video interviews are sponsored by Ringrose Law.