Akka umesh is recovering well,so i think he will be available in 3rd and 4th test.if umesh is not available in 3rd and 4th test natarajan should come in place of umesh,because natarajan is better than saini.
Aswin is main pillar Then Rahane Nattu is waiting to fly Koli please take rest and don't come back and spoil the party, you have no techniques like our great msd
natrajan can make a considerable impact.Hope he is there in 3rd test.David Warner might return to Aus Team so including Nat will make a big difference.