England's record goalscorer Ellen White has revealed she suffered a punctured lung last year while receiving acupuncture treatment, which accelerated her decision to retire.
White, 33, said she was still coming to terms with the "traumatic" injury.
Manchester City had sourced a specialist outside the club to provide her with acupuncture to treat her back problem because of a high number of injuries in the squad at the time.
She announced her retirement this week.
White helped England win Euro 2022 in July and told BBC Sport she knew going into the tournament that she was going to retire from football afterwards.
"If you'd said to me two or three years ago that you're going to retire, I would have said 'absolutely not', but I've got to a time in my career," she said.
"I had a challenging time last year - coming back from the Olympics, I basically punctured my lung, and it was a lot for me to have to go through and a big reason that accelerated my want to retire."
The injury happened when she had returned to her club with a back spasm last summer, having helped Great Britain reach the Olympic football quarter-finals.
It is understood that City arranged for an external specialist to perform the acupuncture as there was an unusually high number of injuries across their squad following the Olympics, and that it is common practice at the club for that to happen.
Acupuncture is a treatment derived from ancient Chinese medicine, where fine needles are inserted at certain points in the body to stimulate nerves.
"It punctured my lung which isn't something that happens normally, obviously," she said.
"It was a really traumatic time for me and something that I'm still figuring out now, still working through."
Ellen White's final appearance as a footballer came in England's Euro 2022 final win over Germany at Wembley'What happened hit me like a train'
The injury left White, who scored 52 goals in 113 appearances for England, short of breath and unable to do any exercise.
"I had to wait for the lung to basically inflate again. I had a needle put into my chest to drag all the air out then hopefully the lung would inflate again - which it has.
"At the time, I think for me, I just got into a zone of: 'I need to get back playing. We've got these games - I want to be back playing for my club; I want to be back playing for England.'"
Her club announced last August that she was set for a brief spell on the sidelines to receive treatment for a "medical issue".
Just over two weeks later, she was back playing and scoring for England against North Macedonia.
"I went very tunnel vision," she said. "It wasn't until a good two or three months later, it just hit me like a train, what actually happened and how traumatic it was."
Despite her quick return to goalscoring form, which included becoming the Lionesses record goalscorer in November, the striker says she is still affected by the injury and suffers "phantom pain" where it feels like it is happening again.
"It's important for me now to tell my story, and say it was a big factor in my year and leading up to the decision of wanting to retire. Obviously there are other factors that come into that as well.
"I don't want it to happen to anybody else again is my main thing. I don't want to walk away from the sport having not told it and not say that I want things in place for it not to happen to anyone else."
Watch Ellen White's full interview with Football Focus on BBC One on Saturday 27 August at 12:00 BST.
