But Jones said Japan's players can counter the brawn with smart 'chop' tackles where the defender throws his arms around an advancing player's legs.
"I've said this to the guys, but I think Japan players are the best chop tacklers in the world. They have to be, to cope with the size of the other teams," said Jones, a key assistant to Japan's head coach Eddie Jones.
"We are the best chop team in the world."
South Africa's coach Heyneke Meyer has acknowledged the awkward threat posed by the Japanese XV.
"We play against the big teams from the Southern and Northern Hemisphere quite often and with them it’s mostly a case of you know what to expect," said Meyer.
"But Japan will pose a different threat," he added. "Our players who play in Japan have warned us to expect a very high tempo game and good, low tackling to stop momentum."