If MSD doesn't retire soon then he's hanging on till 2019
I expect that, come 2019, the pool of batsmen we'll be constructing our top 7 out of will be Nohit, Dhawan, Rahane, Kohli, Pandey, Jadhav, Raina, Yuvi and Rahul Jnr. Who actually ends up in there and in what order is yet to be seen. Kohli will be at 3, and MSD at 4 or 5. Hardik should be the allrounder of choice, Jadeja is definitely playing, Ashwin is probably playing, and our seam attack will be some combo of Bhuvi/Bumrah/Yadav/Shami. Maybe Ishant in case of an injury crises or something. Mishra/Kuldeep the third spinner. Outsiders who may have broken through by then are Pant, Suryakumar, Dhawal Kulkarni, Yuzi Chahal, Krunal, and possibly Washington Sundar/Mahipal Lomror/Sarfraz Khan
Ideally I'd like to see MSD retire, Pant take the gloves, Lokesh opening with one of Dhawan/Nohit/Rahane, and Padey be a lock at 4. Ashwin should be dropped and re-earn his place as a bowler. He defo needs time off. Kuldeep to be groomed for 2019 while Jadeja gets to be the frontline spinner. Chahl stays in the mix. Mishra is good but he definitely falls apart too quickly, not sure I'd trust him in KO games either. Sarfraz Khan and Surykumar Yadav get blooded in to add some firepower to the middle order.