Kevin Pietersen may live to regret his decision to forsake one-day international cricket, and the chance to help win England's first World Cup.
Andy Flower expressed that concern - doubtless a point he made too on the several occasions he tried to dissuade Pietersen from ditching 50-over cricket - as the England coach begins to plan his team's ODI future without their mercurially-gifted batsman.
It is already well-documented that Pietersen's Plan A was to retire from ODIs only, and remain part of the team who will defend their ICC World Twenty20 crown in Sri Lanka this autumn.
But Flower fears Pietersen could one day come to regret more than that absence, especially if England are able to break their World Cup duck - after 10 previous failures, dating back to 1975.
Pietersen had pledged his commitment to that campaign, and the road towards Australia and New Zealand in 2015 - which starts this week with the first of this summer's ODIs against West Indies, Australia and South Africa.
But at some point after his back-to-back, match-winning centuries in what were to be his final two 50-over matches against Pakistan in February, the South Africa-born batsman had an irrevocable rethink.
He made it clear too, during the rain-ravaged third Investec Test against the Windies which finished at Edgbaston yesterday, that he will have no mixed feelings whatsoever even when England take on Australia in five ODIs this month and next.
Flower is left wondering whether that will always be the case.
"I just thought that, after you've retired from sport and you look back at your career, he might think 'crikey, I wish I'd taken part in more World Cups' - and helped win the 2015 World Cup with England'," he said.
"They are great memories, and I think it's a little sad he won't get those opportunities any more."
Pietersen, 32 on June 27, ends his limited-overs career with more than 4,000 ODI runs in 127 matches and 1,176 in 36 Twenty20s.
It need not have been so.
"Kevin was due to be rested for this one-day series with the West Indies, so that would have been the first part of it," Flower said, of an ongoing strategy to avoid player burn-out in a packed international schedule.
"But I don't think resting him for the Australian one-day series and South African one-day series was an option.
"These are two of the best cricketing nations in the world, and we want to put out strong sides against them."
Flower and Pietersen have had to agree to disagree this time, then.
But the coach does not believe the negotiations, reportedly vexed between Pietersen and the England and Wales Cricket Board, have damaged their relations personally.
"I have read occasionally our relationship is not great," he said.
"But actually I think we get on pretty well. We're fairly honest with each other, and I think we have quite a good working relationship.
"I'm not annoyed. I think it's quite sad that Kevin's not going to be playing all three forms of the game.
"I think it's sad for Kevin that he won't be playing all three forms of the game in international cricket."
Pietersen will be restricted to Test cricket only, because the terms of his and others' ECB contracts stipulate no leeway to opt out of one form of limited-overs cricket and continue to play the other.
Flower believes that policy is sound, for cricketing reasons, and because it is incumbent on England to try to protect both the World Cup format itself and their own chances of success in it.
"He's very clear about what he wants to do, so that's his choice," Flower said.
"He told me he didn't want to play one-day cricket any more. He was aware he was on a contract - and I tried on a number of occasions to dissuade him for, what I believe, is his own good.
"But he's a 32-year-old man who makes his own decisions."
Pietersen will therefore be missing for long segments of the time many of his team-mates spend together.
He will be far from the only player limited to just one format, but one of only two by choice.
Test captain Andrew Strauss, selected for only four Twenty20s in his international career, retired from ODI cricket after last year's World Cup.
Flower acknowledges the complication of periods of absence for any senior player, but hopes that situation will not impact either on Pietersen's Test future or England's prospects.
"I think even Andrew Strauss found it difficult, with only playing the Test game," he said.
"Part of our challenge is to constantly work on our unity and harmony.
"I hope Kevin can really enjoy the years of Test cricket that are ahead of him - and I hope he does brilliantly in them."