'I give a lot of importance to my preparation and that is why I came here Friday, so I can prepare well and be ready to go when the first match begins,' Somdev told IANS.
'My job has always been to win two singles matches for India. The tie is an intriguing one as South Africa have a very dangerous team.
'As far Rohan is concerned, his knee is fine and he is playing well. We have been preparing well for this tie.'
The two time National Collegiate Athletic Association (NCAA) champion said the courts here are not that fast and that he is comfortable playing on the indoor courts.
'I have become more comfortable with each passing practise session. The courts are not that fast but the conditions are. The balls travel much faster through the air,' said Somdev, who played a crucial role in India's win in the away-tie at Chinese Taipei in February.
'I am fine playing indoors, too, as I played a lot of college tennis indoors.'
For South Africa, the return of their top player Wesley Moodie will give them an upper hand in the doubles tie. Moodie will team up with estranged partner Jeff Coetzee, with whom he controversially terminated his partnership earlier this year.
South African captain John-Laffnie de Jager is confident of the home team's chances.
'I am very positive and excited about our chances against India,' he said. 'We have won the last three ties we played here in Johannesburg at the indoors and on high altitude, so we are confident.'
India like South Africa had last played in the World Group in 1998. South Africa is looking to win its 11th tie in a row.
South Africa have made four World Group appearances.
This is the second successive year that Indian reached the World Group play-off, having lost to Romania last year.