Most expected his next move to take him to Europe. Instead, he is headed to Salt Lake City.
United on Monday shipped its 17-year-old midfielder along with former UCLA goalkeeper Nick Rimando to Real Salt Lake for reserve goalie Jay Nolly, a major player allocation and significant future considerations.
"It was not an easy decision," United President Kevin Payne said. "Freddy has been an important part of our team, but we saw an opportunity to do something for both him and for the future of our team."
The deal, formulated only in the last week, abruptly ended Adu's career in Washington after three up-and-down seasons.
His signing at age 14 and his stay helped bring more exposure to United and Major League Soccer.
But it also created headaches for Coach Peter Nowak, who tried to balance the needs of his team with the developmental requirements of a player who had been attracting interest from European clubs since he was 12 and whose $550,000 salary is more than five times the league average.
Adu had 11 goals and 17 assists in 87 regular-season appearances and, in his rookie year, helped United win the 2004 championship.
Adu will be reunited with Salt Lake Coach John Ellinger, who oversaw Adu's development in the U.S. under-17 residency program in Bradenton, Fla.