The 40-year-old spent five years as a player at Sincil Bank before becoming a goalkeeping coach at Doncaster Rovers.
Ex Imp player and manager John Schofield is also at Whaddon Road as assistant manager, and appears to have a good future in the game despite being burned as Imps manager a season and a half ago.
Martin Allen told BBC Gloucestershire: "He comes highly recommended. We've seen from Scott Brown's development how important a position it is."
He added: "It's not just being a coach, they are almost personal mentors. It's a specialist position and in an ideal world we'd like one full time, but that isn't possible here."
Allen also crowed about the arrival of Schofield last season.
"He's a good coach, he's bright and bubbly and good around the players. 's been well-documented I've been working on my own and it's been very difficult to get to football matches as well as taking training every day. "
Interestingly enough Barry Richardson and John Schofield never played in the same Imps side together.
Richardson replaces Alan Fettis who recently left Cheltenham to join Premier League Sunderland as their goalkeeping coach.