The US international has criticised Beckham for his lack of commitment to the team in 2008 but admits he should have approached the player about it and not gone off and told a reporter.
"I'm not going to apologize for the way I felt," Donovan said in an interview with The Times.
"What I feel badly about is that I should have been a man and told David how I felt as opposed to telling a reporter.
"David and I will sit down when he gets back and just talk it through. What you don't get from reading a few excerpts and what you do get from reading the whole book is that we all want David to be here. We all want him to succeed, and he wants to succeed.
"Something happened at some point last year where a switch went off, and that's what I want to talk to him about and we'll figure that out man to man."