There's no argument about these two opening. Not only do both complement each other, they are also runaway match-winners in their own right. Just that in Kohli's absence, they won't have the luxury to be too adventurous at the start of the innings, for one of them must bat till the 30th over. Also, it'll be interesting to see if their approach changes significantly when there isn't the cushion of Kohli walking out at 3.
Rayudu averages 50 in ODI cricket, and that in isolation must make you wonder why he was dropped in the first place. But a closer look at the stats will tell you that the average is inflated because of the number of times he has remained unbeaten. The fact that his strike rate is 76 and not in the high 90s isn't ideal for someone batting lower down the order. His impressive IPL returns brought him back into contention, but it shouldn't be lost on the team that the majority of those runs came as an opener. He has improved his attacking play against pace in addition to his competence against spin. But since he isn't your ideal finisher, it would be wise to let him audition for a place in the middle order by batting him in Kohli's place.
In Kohli's absence, there's more focus on Dhoni's role and responsibility of not just holding the middle order together but also finishing some games. While his IPL returns suggested that he has turned back the clock, the limited-overs leg of the England tour hinted otherwise. I'd like him to bat at five and use the Asia Cup to find a role that's best suited for him at this stage of his career. Dhoni has been vocal about his preference for batting at four, but having your most experienced players in the top four positions is a disaster waiting to happen. Also, batting in the lower order, against the old ball and with fewer field restrictions, is the tougher pursuit in ODI batting, and it would be grossly unfair to have only the younger lot lift that load.
These are the two allrounders who need to bowl a few overs and play the role of finishers. For the longest time, India went in with only five bowling options - Pandya being the fifth. But while his bowling has improved, he's not your ideal fifth bowler in any white-ball cricket. Even Mumbai Indians have him as one of six options. Also, not having a sixth bowling option doesn't allow you a cushion if one of the lead five has a bad day, which happens every now and then.
Playing four bowlers, Bhuvneshwar Kumar, Jasprit Bumrah, Kuldeep Yadav and Yuzvendra Chahal, is a straightforward choice, but Bumrah's workload will need to be monitored right through the tournament. He bowled a lot of overs in the three Tests he played in England, and the heat of the UAE will be unrelenting. It would be wise to play Khaleel Ahmed in both league games. Also, playing Axar Patel in place of Kuldeep or Chahal in the opening game against Hong Kong wouldn't be a bad option, for he's unlikely to get too many games leading up to the World Cup.
Aakash Chopra is the author of three books, the latest of which is The Insider: Decoding the craft of cricket. @cricketaakash