Retout will make fact-finding visits to major Australian rugby league clubs during his absence.
Roberts said: "This was a decision made by Paul with the full support of Geoff Moss, Paul Atkinson and myself."
The Blue Square Premier club share the Racecourse with Welsh Super League side Crusaders, who moved there for the start of this season.
Roberts added: "As part of his sabbatical, Paul intends to travel to Australia to spend time looking at, and gaining knowledge from, how NRL clubs operate," said Roberts.
Source: BBC Sport
Source: BBC Sport