Heather Knight has admitted that England were "mentally fatigued" and struggled for motivation in the final two ODIs against Australia with the Ashes' fate already decided.
England were bowled out for 129 and 163 in the second and third ODIs, losing with 88 and 82 balls to spare respectively. They were heavily beaten in the only T20I that was played in full - though posted a competitive 169 for 4 - and were narrowly beaten in the first ODI, with a dramatic, drawn Test match sandwiched in between.
Australia retained the Ashes with their victory in the first ODI and England have struggled to strike a balance between playing their best XI and managing their squad with an eye on next month's World Cup in New Zealand. Kate Cross (wrist) and Katherine Brunt (side) missed the third game, with Emma Lamb brought in for an ODI debut.
"The last two games, we probably haven't competed as much as we would have liked," Knight said. "We've been a little bit fatigued and not quite us as a side, to be honest.
"It's been a really good series, particularly the start of the Test match and a few really tight games where we went toe-to-toe with Australia but couldn't quite win those big moments and be ruthless in finishing off games. We put ourselves in opportunities to win matches but weren't quite able to get it over the line.
"[It was an] unbelievable Test match to be involved in - absolutely brilliant. I was proud of the girls how they went about it, but I think mentally it probably took a little bit out of us. It's the same for both teams and Australia were able to turn it around for those ODIs.
"But yeah, I do think the last two games we've probably been a bit mentally fatigued - [we've had] a couple of injuries kicking around and a few people we've had to test a little bit with our eyes on the World Cup. That's played a part too."
England's opening World Cup fixture is also against Australia - in Hamilton on March 5 - and their winless run against them in ODIs now extends to six games after consecutive 3-0 defeats in the 50-over leg of Ashes series.
Knight insisted that her team had "not become a bad side" and that the opportunity to regain physical and mental freshness before the start of that tournament meant the Ashes result would have little bearing on the World Cup opener.
"I don't think the last two games matter too much," she said. "Mentally, we found it hard to stay up with the Ashes already gone. Obviously that was our aim. But I believe we can beat Australia on our day, if we get our batting and bowling together, be a little bit more ruthless - but 100 percent believe we've got the players to compete in that first game, and it's a one-off game. It shouldn't really matter too much.
"[This series] was very different to 2019 I think. Our belief and mentality has been totally different. I think we've gone toe-to-toe and tried to go at Australia, which I think is a good strategy against them. But we haven't been able to be quite ruthless [enough] in those big moments and they're the sort of team that don't give you too many chances, so when you're on top you have to nail it down.
"We haven't become a bad side after this Ashes. We have to reassess and go again. [We'll be] ready for the World Cup and hopefully gain some mental freshness and freshen up physically as well."