Gradi returned to the managerial hot-seat from his role as technical director on Tuesday following the decision to replace Steve Holland.
The veteran boss has wasted little time in re-signing midfielder Lunt on loan from Sheffield Wednesday until January 3.
He will go straight into the squad for Saturday's clash with Stockport County as Michael O'Connor is serving a one-match suspension and Steven Schumacher is out for six weeks following surgery.
Lunt had made 432 appearances in all competitions for the Railwaymen and spent time last season at Gresty Road on loan.