"No. 4 is just a number, anyone can fit in," Ganguly said. "I really don't think that anybody is born as an opener or No. 3 or No. 4. I had started in the middle order in one-day cricket and was asked to open when Sachin [Tendulkar] was the captain. Sachin also started at No. 6; when he opened, he became a world-class player.

"So anybody can play at No. 4. There's Virat Kohli for No. 4; there's Shreyas Iyer once he does well at the Asia Cup; there's KL Rahul. India has enormous talent.

"I keep getting asked that we don't have this, we don't have that, but I think we have too much; that's the problem. I think for No. 4 what Rahul [Dravid], Rohit [Sharma] and the selectors need to do is decide that this is my No. 4 and continue with him till the World Cup.

"One batting slot doesn't make so much of a difference because you don't win a World Cup just with No. 4. There's no hard-and-fast rule that you need someone at No. 4, all you need to do is decide and let them play [at that position]."

Ganguly upbeat about Bumrah's return

"He bowled well [on his comeback] and obviously the opposition is going to be different," Ganguly said of Bumrah's return. "But it's his first tour after a long time and he's just been eased in. I'm looking forward to the Asia Cup; he's been bowling quick and players in the nets have been telling that he's hitting the bat hard. I saw him bowling in Ireland and he bowled good pace."

India will be hosting the ODI World Cup this year, in October-November. The last time they were hosts, in 2011, they won the trophy. But their last ICC title was the 2012 Champions Trophy, in England under MS Dhoni.

"They get to the semi-finals, they play the WTC [World Test Championship] finals; once they get there they'll cross the bridge," Ganguly said. "I have a lot of faith in this team, and hopefully we'll see a side that will play the Asia Cup, the Australia series and the World Cup. It's important for everyone to be in good form and be determined. One batting position or one player doesn't win you the World Cup."

After the Asia Cup runs from August 30 to September 17, India will host Australia for three ODIs on September 22, 24 and 27 before the World Cup starts on October 5. India's opening game in the World Cup will also be against Australia - on October 8 in Chennai - and it is likely that the same pool of players traveling for the Asia Cup will be picked for the World Cup, after the squad is trimmed from 17 to 15.