The former MLS MVP and club captain will be eligible for the re-entry draft after a disappointing season in the nation's capital.
The club announced Thursday it had declined the option on the 2011 MLS MVP, who will be eligible for the re-entry draft. The decision comes four days after United wrapped up a 3-24-7 season, during which it set the league records for fewest wins, lowest goals per game and worst goal differential.
"This was a difficult decision to make, but it was one that we felt was best for our team to move forward into next season and beyond," said general manager Dave Kasper in a press release.
United acquired De Rosario in a June 2011 trade with the New York Red Bulls for Dax McCarty. After compiling 13 goals and seven assists in 18 games for D.C. that season, he was named the league MVP and earned a new two-year contract that made him the club's highest-paid player.
Although De Rosario had seven goals and 12 assists in 2012, a sprained knee ligament sidelined him for United's stretch run and most of the playoffs. He then notched just three goals and two assists this past season while earning a base salary of $600,000, though he did score five goals during United's run to the U.S. Open Cup title.
De Rosario addressed the news on his Twitter account Thursday morning, writing: "So humbled by all the support & appreciate ur words of encouragement. A new chapter is soon to begin."