Sarginson, who joined the Broncos juniors from Hemel, is among the players the Stags are hoping to play under the dual-registration scheme.
London's head of youth performance Phil Jones said: "It is an exciting time to see the arrival of Hemel as a professional club and I hope this partnership will provide some support to their development, as well as allowing some of our squad players the opportunity to compete in a very exciting Championship One competition."
Hemel chief executive Bob Brown said: "We are delighted that, as a result of the partnership agreement, the three players that have signed dual registration contracts are ex-Hemel juniors.
"It is great to welcome back Miles Mcleod, Jack Molloy and potentially Dan Sarginson to Pennine Way in our first year in Championship One in 2013."
- Sports & Recreation