South Africa, who have already lost their first match will need to win this one to stay in the hunt for a semi-final spot, while Sri Lanka also with one win from two matches need a victory to book their semi-final place.
South Africa, who came to India as one of the favourites to win the tournament, suffered a jolt when they crashed to a defeat against New Zealand in Mumbai. Graeme Smith's men now have to improve there batting by leaps and bounds if they are to remain in the competition.
The South African camp, meanwhile, are debating whether to go in with an extra batsman or bowler, if their coach Mickey Arthur's statement is anything to go by. ''We are considering one change in the team that played the Kiwis, possibly bringing in AB de Villiers.
The decision we have to take is whether we want to play an extra batsman or a bowler,'' he has said.
The South Africans who played an extra bowler in their 87-run defeat against New Zealand are also thinking of a change in strategy that will kick off their campaign by bringing in AB DeVillers as the extra batsman. The final decision, however, is expected to be made only this evening.
Andrew Hall, one of South Africa's leading wicket-takers in ODIs, a specialist death overs bowler and generally a versatile all-rounder, is thought likely to lose out in case such a decision is taken. Whatever the combination, their remaining two games - they play Pakistan on Friday - are pressure-laden must-win matches.
South Africa will also have to deal with ace off spinner Muttiah Muralitharan along with medium pacers Chaminda Vaas, Lasith Malinga and Fervez Maharoof to back the off spinner up. The South Africans have to be at their best when it comes to batting against a class attack on wickets, which suit them, if they have to win the match and stay in the tournament.
The Sri Lankans, meanwhile, have put the defeat against Pakistan behind them and are looking to go further up as was seen with a total professional display against the Kiwis. The men from Emerald Isles also need to win this match as that would give them two wins from three matches, this being their last match, to be sure of a semi-final berth.
The Lankans apart from a settled bowling attack also have a flexible batting line-up with opener Upal Tharanga in the form of his life having already hit two centuries and a fifty in five matches in this championship so far. To back him up is the veteran Sanath Jaysuriya and a strong middle order in Mahela Jayawardene, Kumar Sangakkara, Marvan Atapattu and Tillakratne DIlshan to back up the openers.
The wicket unlike the one in Mumbai is likely to be a typical one-day wicket with runs there for the taking. The dew factor is also not expected to play a big role as seen in the earlier two matches at this venue.
South Africa: G Smith (c), J Kallis, L Bosman, M Boucher (wk), AB de Villiers, H Dippenaar, H Gibbs, A Hall, J Kemp, C Langeveldt, A Nel, M Ntini, R Peterson and S Pollock.
Sri Lanka: Mahela Jayawardene (c), Marvan Atapattu, Malinga Bandara, Tillakratne Dilshan, Dilhara Fernando, Sanath Jayasuriya, Chamara Kapugedera, Farveez Maharoof, Lasith Malinga, Murali Muralitharan, Ruchira Perera, Kumar Sangakkara (wk), Upul Tharanga and Chaminda Vaas.