Rahul Dravid's line-up was one of the in-form sides in ODIs in the first half of 2006 and at the end of April lay third in the table, three rating points behind the Proteas.
But since then it has won just three of its last 13 outings (with eight losses and two no results), which has seen it slip to the fifth spot, 21 rating points adrift of leaders Australia and 12 points behind South Africa.
The fact India is coming up against a South Africa side that lies second in the Championship table and is on home territory only appears to heighten the size of the challenge in front of Dravid's players.
But India still has plenty of positives to draw upon, not least the apparent strength of its bowling stocks. It has three players, spinner Harbhajan Singh and pacemen Irfan Pathan and Ajit Agarkar, in the top 20 of the rankings for ODI bowlers.
And while Yuvraj may be missing from the squad, India still has two players in the batting top 20, power-hitter Mahendra Singh Dhoni (sixth) and captain Dravid (15th) and a fully-fit Sachin Tendulkar in the 21st position.
A 3-2 series defeat will see India remain on 110 rating points but even that will be enough to lift it back above Pakistan and into fourth spot when the ratings are recalculated to three decimal places.
Whereas a 3-2 win will lift India to 112 points (South Africa 119), a 4-1 success will see it rise to third place with 114 points (South Africa will drop to 116) and a 5-0 clean sweep will see Dravid's team move into second place with 117 rating points (South Africa will drop to 113 points, although it will remain ahead of New Zealand).
For Proteas as well, a lot is on the stake as a convincing series win will see them close the gap on Australia at the top of the table, with a 4-1 success taking it to 124 points (India 108) while a clean sweep of all five matches will lift it to 127 rating points (India 106, dropping it below the West Indies, currently in seventh place), just four behind Ricky Ponting's world champions.
The batting list is headed by the ICC ODI Player of the Year Michael Hussey of Australia, clear of Gayle, England's Kevin Pietersen and Adam Gilchrist of Australia. Dhoni is India's highest ranked batsman, in joint sixth place alongside Australia captain Ricky Ponting.
Shaun Pollock tops the bowling table ahead of Glenn McGrath of Australia and the West Indies' left-armer Ian Bradshaw. India's top-placed player is Harbhajan, in 11th spot.
ICC ODI rankings:
Team: 1) Australia (131 pts), 2) SAfrica (122), 3) New Zealand (113), 4) Pakistan (110), 5) India (110), 6) Sri Lanka (108), 7) West Indies (106), 8) England (99), 9) B'desh (34) and 10) Zimbabwe (30)
Batsmen: 1) Mike Hussey (Aus, 821 pts), 2) Chris Gayle (WI, 804), 3) Kevin Pietersen (Eng, 776), 4) Adam Gilchrist (Aus, 769), 5) Andrew Symonds (Aus, 753), 6) Ricky Ponting (Aus, 740) and Mahendra Dhoni (Ind, 740) 8) Ramnaresh Sarwan (WI, 739), 9) Graeme Smith (SA, 724) and 10) Kumar Sangakkara (SL, 723)
Bowlers: 1) Shaun Pollock (SA, 862 pts), 2) Glenn McGrath (Aus, 799), 3) Ian Bradshaw (WI, 774), 4) Nathan Bracken (Aus, 752), 5) Brett Lee (Aus, 741), 6) Shane Bond (NZ, 730), 7) Daniel Vettori (NZ, 725), 8) Murali Muralitharan (SL, 712), 9) Makhaya Ntini (SA, 711) and 10) Chaminda Vaas (SL, 706)
All-rounders: 1) Chris Gayle (WI, 478 pts), 2) Shaun Pollock (SA, 451), 3) Sanath Jayasuriya (SL, 370), 4) Andrew Flintoff (Eng, 365), 5) Andrew Symonds (Aus, 337)