KL Rahul says India face a "very, very difficult decision" over who bats at number five in the first Test against South Africa at SuperSport Park.

Rahul, vice-captain in the absence of the injured Rohit Sharma, gave a strong indication that the tourists will persist with playing five bowlers in the Boxing Day Test behind closed doors in Centurion.

He said: "I think more teams have started playing [five bowlers], because, you know, every team wants to pick up 20 wickets, and that's the only way you can win a Test match.

"We've definitely used that tactic, and it's helped us in every Test match that we've played away from India. I think the workload also becomes slightly easier to manage with five bowlers, and when you have that kind of quality, you might as well use it."