South Africa routed the home side by 177 runs in Perth with just two fast bowlers and debutant spinner Keshav Maharaj after pace spearhead Dale Steyn was injured when bowling in Australia's first innings.
Left-armer Maharaj took four wickets in a successful debut at the WACA but may be rested at Bellerive Oval as Faf du Plessis' side bid for an unassailable 2-0 lead in the three-match series.
"There is a possibility of that," Du Plessis told reporters in Hobart on Friday. "If it becomes a really shortened game ... that's something we will look at.
"It looks like there's going to be a little bit of rain tomorrow, so if it rains for the whole day it becomes a four-day game.
"The pitch is going to be under covers, the ball is going to be wet."
Heavy rain is forecast for the opening two days of the test, which could frustrate both sides' hopes of victory.
South Africa have Morne Morkel and Kyle Abbott vying to replace Steyn, who suffered a fracture in his shoulder and could be out of the game for more than six months.
