England allrounder Ben Stokes said he knew during the Ashes series that he was going to reverse his decision to retire from one-day cricket in time for next month's World Cup, and that he had ruled out a comeback to throw the media off the scent.

The talismanic 32-year-old, the architect of England's maiden 50-overs World Cup triumph in 2019, announced his shock ODI retirement last year citing his heavy workload.

As speculation that he might return to the format for England's title defence swirled during the Ashes in June and July, Stokes quashed talk of a possible return to the ODI squad, citing a nagging knee injury.

However, he returned to the England set-up last month ahead of their World Cup title defence in India, and gave another example of his explosive batting in the third ODI against New Zealand on Wednesday, smashing 182 off 124 balls.

"Obviously I've been asked a lot about my knee over a long period of time, so I just said that to leave it," Stokes said of his previous comments about the possibility of an ODI return.

"I knew that I'd be playing in these games and potentially in the World Cup then when I said that, but it was just the easiest thing to say that and put you (the media) off the radar."

England have agreed to play him as a specialist batter, preferably at No 4, and he said the clarity about his role helped him bat with more freedom.

"This is the first time that I've been clear in my mind that that's the one thing I can focus on," Stokes said.

"I think over the last 18 months, every day has been, 'will I bowl, will I not bowl?' Now, I know that I can just focus on that ... Having that clarity in my head contributes to that."

England take on New Zealand in the final ODI at Lord's on Friday. They lead the four-match series 2-1.