Rabada suffered a hamstring injury in training in June, and there had been doubt over his participation in the series, but he played in a two-day intra-squad match in Durban on Sunday and Monday, and Prince said he bowled really well.
“He’ll continue to be involved, obviously, in training over the next few days leading up to the match, but it’s fair to say that he’s obviously not going to be 100% straightaway," Prince said.
“But he is looking good, and he will train with the squad for the rest of the weekend, and I think we will leave a call to be made as late as possible,” Prince added in a virtual press conference.
When the preliminary squad of 18 players was named for the Australia test series last month, coach Shukri Conrad warned they would take no chances with the 31-year-old Rabada, who has taken 340 test wickets.
"We will give a decision as much time as humanly possible, but we also don't want to take a call based on desperation," he told reporters.
Rabada’s inclusion would be a major boost to the hosts given his role as the team's leading quick bowler, but the home side still have plenty of bowling options if they decide not to risk him.
Corbin Bosch, Gerald Coetzee, Marco Jansen, Anrich Nortje and Dane Paterson have all been selected as pace bowlers and spinners Simon Harmer, Keshav Maharaj and Senuran Muthusamy are in the squad too.
“We're blessed with whatever combination we choose,” said Prince of the possibility of fielding two spinners. “We can take 20 wickets whether it is seam heavy, or whether it is two spinners. What plan we go with depends on the surface,” he added.
Sunny conditions are expected over the weekend in the seaside city.