Former United States team-mates Brad Friedel and Tim Howard have become embroiled in an argument about an incident from more than a decade ago.
In his forthcoming autobiography, Everton goalkeeper Howard, 35, claims Friedel actively tried to block his move to Manchester United in 2003.
Friedel, though, has denied the allegation and is demanding an apology from the current US number one.
"It is complete garbage," the 43-year-old Tottenham keeper told ESPN.
"I never sabotaged and I never stood in the way of Tim Howard getting a work permit. This is ludicrous."
Howard completed a £2.5m move from Major League Soccer side Metrostars to United 11 years ago, but needed a work permit.
|Tim Howard has made over 200 Premier League appearances since moving from the United States in 2003|
|He spent four years at Manchester United before joining Everton in 2007|
|Howard has 104 international caps|
In his book The Keeper, Howard says Friedel, then playing for Blackburn, refused to endorse his application with a letter of support.
"The legal team at Manchester United told me that Brad hadn't merely refused to sign a statement on my behalf, he had actively tried to block my transfer," Howard writes in the book.
"He'd written to the appeals committee suggesting that I shouldn't be given a work permit at all."
Friedel says he was asked to sign a letter of support by then US coach Bruce Arena, but did not because he felt it was inaccurate.
"It said that I had been in direct competition with Tim Howard for the starting job on the USA national team for the last two years, when anyone who follows soccer knew it was between Kasey Keller and I," he added.
"Yes, I refused to sign that. We got the letter and said 'We have to change this, because this isn't true'. We made our changes and sent it back. They didn't like what I was going to sign so they didn't use it. And that was the end of the matter."
The Professional Footballers' Association said on Wednesday it had been asked to confirm that it "did not receive any correspondence" from Friedel with regard to denying Howard a work permit.
Friedel played for the United States between 1992 and 2005, while Howard has played for the national team since 2002.