India take on South Africa in a five-match one day series starting on Wednesday. With the World Cup just around the corner, India will look forward to improve rankings as a win in the five-match series against South Africa could help Mahendra Singh Dhoni's men become the number one ODI team.Currently ranked second in the ICC ODI rankings, India are expected to face stiff competition for the top spot from top ranked Australia, world number four South Africa and fifth ranked England.Meanwhile, India'a injury woes continued with medium pacer Praveen Kumar heading home after sustaining an elbow injury. Ishant Sharma has been called as Kumar's replacement.Virender Sehwag and Gautam Gambhir have already flown back home to nurse their injuries, while S Sreesanth developed tennis elbow a few days back.