I assume Washington is out because they want their best spinner at Adelaide. Having Reddy in the team gives them a lot more flexibility with the bowling line up so they feel less like they have to pick Jadeja or Washington as a stronger batter at 7 and then four pace bowlers.What I dont get is why Washington was forced out. Rohit was to walk in anyday, but has proven that he can't bat in the middle. KLR, on the other hand makes Perth look like a flash in the pan.
I think they felt they can't drop KLR after his performance at Perth and Rohit in the middle order potentially suits the team better. Rahul allows the stroke makers to play around him and then Rohit can play freely and aggressively. Of course that plan would work better at 280 for 4 not 80 for 4.