I think the team wanted to try out the bowling combination which they will be playing in most of the matches - Zaheer, Munaf, Agarkar, Harbhajan and a 5th bowler, who could be Pathan or Sehwag/Sachin/Yuvraj. They havent played Pathan because he is not fully fit. Its better not to risk him when he is not fit. Sreesanth, according to me, is only a backup option in the ODIs.