The 37-year-old has been working as a set piece coach as part of the staff of former Rovers boss Darren Ferguson in a position that is expected to be formalised in the coming weeks.
Butler saw his contract as a player at Rovers cancelled last month by mutual consent and immediately joined National League North side Boston United.
He made just a single appearance for the Pilgrims earlier in pre-season and is understood to still be contracted to the club, who kick off their league campaign this weekend.
Butler also remains in charge of the Belles and it is unclear how his new role will impact that going forward.
The Balby-born centre half continues to hold aspirations of moving into management in senior men’s football and says his experience in charge of Rovers did nothing to deter him.