Piggy, who won the London test event before the Olympics, will be riding Westwood Mariner and Gemma will ride Tropique.
With just over a year to go before WEG (23 August- 7 September 2014) the event will act as a trial run for organisers and competitors.
World class performance manager for Eventing, Yogi Breisner said: “The test event is an important part of the preparations.
“It gives the staff a chance to get used to the facilities and helps with the planning for next year.”
For an exclusive interview with Piggy French don’t miss his week’s Horse & Hound magazine out today (1, August).
This news story was first published in Horse & Hound magazine (1 August 2013).