The "soap opera" dispute between United States head coach Gregg Berhalter and the Reyna family is "a sad and pathetic day for US soccer," says ex-American international Heather O'Reilly.
Borussia Dortmund midfielder Gio Reyna, 20, did not start a match for Berhalter and the US at the World Cup in Qatar.
Reyna's mother Danielle has since reported Berhalter for kicking his wife when they were teenagers.
"No one wins in this situation," O'Reilly told BBC World Service.
"To bring up old dirty laundry 30 years in the making is just something else in my opinion.
"I would never condone violence or domestic violence, but this was 31 years ago, this was an incident that was reconciled - they [Berhalter and wife Rosalind] have a successful marriage of 25 years."
Berhalter is under investigation by US Soccer after admitting the allegation.
During a speech at a leadership summit in early December, Berhalter, 49, said an unnamed player was nearly sent home from the World Cup for "not meeting expectations on and off the field".
After those comments leaked out, Reyna - capped 16 times by the US - revealed on Instagram he had apologised to his team-mates and Berhalter for his attitude.
Reyna said he had been told by Berhalter that his role at the tournament would be "very limited" and that he let it affect his "training and behaviour".
"I think they [the Reyna family] are frustrated that Gio's name did get dragged in mud," said O'Reilly, speaking to the World Football show.
"But this was just a low, low, low manoeuvre. And one that I just think is nasty.
"This is like youth soccer gossip at the absolute highest level and it's just really sad and, honestly, a pathetic day for US soccer."
'Berhalter may not recover, Gio will be mortified'
Gregg Berhalter (back row, third from left) and Gio's father Claudio Reyna (front row, left) were team-mates in the US squad that reached the quarter-finals of the 2002 World CupReyna's mother said she reported Berhalter to US Soccer because it was "unfair" that "people were trashing" her son when the head coach had done something "much worse" at a similar age.
Her husband, and Gio's father, is former US captain Claudio Reyna, who played for Rangers, Sunderland and Manchester City during eight years in the UK between 1999-2007.
Mrs Reyna won six caps for the US women's national team and was the room-mate of Berhalter's now wife Rosalind at the time of the incident.
Gregg Berhalter and wife Rosalind, pictured on a visit to Oktoberfest during his time with German club 1860 MunichBerhalter's contract expired on 31 December and it is not yet known whether he will be offered a new deal.
O'Reilly believes the spat could cost him his job despite leading the US into the World Cup knockout stage last month.
"Before this, honestly, I would have said that Berhalter should be given a new contract - I think what the US national team did at the tournament was admirable," she added.
"But he did speak at the conference about a young player - and then that got leaked out because everybody knew that he was talking about Gio.
"He made a mistake. A mistake he probably regrets and then it obviously snowballed and he had no control over that snowball building.
"That is something I don't think he can recover from because of all that's come with it."
O'Reilly believes Reyna will be "mortified" by his parents' involvement in the matter, but expects the saga will do less damage to him than to Berhalter in the long-term.
"I think it will take a little bit of time to rebuild his reputation and he has a lot of work to do on the pitch," said O'Reilly.
"He's 20-years-old, he has a lot of game left in front of him and a lot of football in his legs and I think if he learns from this and does things right he will get another chance."