Forward Nikita Parris has apologised to former international team-mate Eniola Aluko for her show of support for then-England boss Mark Sampson in 2017.
Parris, 26, ran to celebrate with Sampson, who was accused of racially discriminating against Aluko and Drew Spence, after a goal against Russia.
An inquiry later ruled that Sampson had made unacceptable remarks to Aluko and Spence.
"Eni, I am sorry that my thoughtless actions caused you hurt," wrote Parris.
"At the time I focused more on what I believed was showing unity when really it did nothing of the sort, it showed a lack of empathy, understanding and ignorance by singling out a voice who needed an ear to listen and a support system to help.
"I am now able to understand how I have been part of the problem which I aim to fight and eradicate.
"I am a proud black woman, I understand I have a social responsibility to help create change through my platform."
Aluko said in November 2017 that Parris' celebration was not respectful considering the complaints against Sampson at the time.
"I think it was naive and perhaps wasn't the best thing to do for the players," she said.
"Some of them may have a special relationship with Mark Sampson and they have every right [to celebrate with him], but I think about the sensitivity at that time, and it wasn't respectful."
Aluko, 33, retired from football in January, having won 102 England caps, the last coming in 2016.
The same year she made allegations of misconduct against then England boss Sampson - the Football Association apologised to Aluko in October 2017 for racially discriminatory remarks made by Sampson, but an inquiry cleared him of bullying accusations.
Parris, who moved to Lyon from Manchester City in summer 2019, played a key part in England's run to the semi-finals of the women's World Cup that year.
Sampson was sacked the day after Parris' celebration in a World Cup qualifier over "inappropriate and unacceptable" behaviour in a previous role as Bristol Academy manager. He later won a settlement from the FA and is now part of League Two Stevenage's coaching staff.