Instead, she and one-year-old son Otis will support husband and father Tim aboard Ringwood Sky Boy and Bango.
"It would be nice if she was competing, but her focus is on the World Games," Tim Price told Radio Sport.
"Just keeping up with her is half the battle. It's good fun and we egg each other on."
Price rated his Burghley chances, particularly on Ringwood Sky Boy who has contested the event four times and registered second, fourth and fifth-placed finishes.
"We've done all except win it, but nothing else compares to Burghley.
"Badminton is tough as well, but the terrain plays a big part. They build it [the cross-country course] right up to the maximum width and height.
"The way it's set on the land means things can actually look bigger when you're travelling down hills, like when you head into a water jump and have something a short distance afterwards. It's gruelling."
Todd's quintet of victories came between 1987 and 1999. He agreed the cross-country terrain, designed for the last 14 years by 1973 champion Captain Mark Phillips, made it the toughest of the six four-star events to win.
"Badminton is more on the flat, whereas Burghley is rolling, and with that you get more difficult questions at the jumps.
"Mark Phillips normally builds a strong four-star test and the two horses I've got [Kiltubrid Rhapsody and NZB Campino] have plenty of jumping ability."
NZB Campino, who Todd described as "a great old campaigner" has had top 10 finishes at all the northern hemisphere four-star events. Kiltubrid Rhapsody finished sixth this year at Badminton in his first four-star start.
Nicholson is the only rider to win the event three consecutive times - and on the same horse, Avebury.
Last year he said Burghley encapsulated everything he loved about England.
"It's held at the end of summer, people are out having picnics on the course, and you think 'this is why we do it'.
"It's a big competition but a relaxed atmosphere. When you're competing it's full-on, but it's easy to get away from it."
The event begins with the dressage on Thursday night (New Zealand time) and concludes with the showjumping on Monday morning. – interviews Matt Brown
New Zealand winners at the Burghley Horse Trials
Sir Mark Todd – 1987, 1990, 1991, 1997, 1999
Andrew Nicholson – 1995, 2000, 2012, 2013, 2014
Blyth Tait – 1998, 2001
Caroline Powell - 2010