Why should they bench one of Kohli, Raina and Yusuf for Yuvraj? What has he done over the past year and a month to be in the side? Precious little. His batting has been woeful, and it makes no sense to keep someone picked as a specialist batsman who's scoring so little. That bowling excuse is no excuse to keep a non-performing batsman, as you get more from Yusuf (which Dhoni doesn't agree on) and he's also scoring enough runs from a difficult position, and you have far better bowlers in Ashwin and Chawla. Besides, both Kohli and Raina are getting enough runs to play as batsmen alone.
Looking at the seam options, while the injury to Praveen Kumar was unfortunate, the coming of Sreesanth is a good thing for the Indian team. He has the best ODI record inside of India and Sri Lanka, chipping away a wicket every 25 deliveries, and maintaining an average of 27. While his economy is on the higher side, so is Praveen Kumar's, and he has a weak strike rate of 70. In addition, Praveen is another dreadful fielder, and the Indians are carrying two more in Nehra and Munaf, both of whom have struggled in India.