Let's just see how it shapes up now. Zaheer seems a perpetual injury worry, and all the bowlers, Zaheer included, are poor on flat decks, and wear out after their fifteenth over. Maybe Pankaj has a shout at that. There's a little too much competition between Zaheer, Ishant, Sreesanth and Praveen, and it will be difficult for Pankaj breaking in there. On the other hand, with India's bowling weakness flaring up due to the lack of a fifth bowler, if he can score runs, adding up to Bhajji and Praveen, he has a very strong case. Pace is a difficult ask from the man, much as it is a screaming requirement, so he needs to get both wickets and runs for his FC team, then for India. He offers just as much with the ball as the top four and if he can get runs on a regular basis, he can play as a third seamer in India or even the fourth seamer abroad. He should easily sneak in ahead of Munaf Patel.
Replacing one of Zaheer, Sreesanth, Ishant or Praveen is out of the question, and even then, he can't help India win matches, so the best he can do is as the fifth bowler.