All head office staff, including chief executive Justin King, have to work at least three days in stores each between December 12 and January 3.
In addition, Sainsbury has recruited 5,000 extra temporary workers, with a further 5,000 part-time store staff having extended hours over Christmas.
Head office staff are being encouraged to focus on their relevant skills. For example, wine buyers would assist in stocking the alcohol aisle and offer category advice to customers.
Key areas have been identified as replenishment of the gifting zone, produce and fresh foods; helping at the checkouts; and showing shoppers where products are.