"I have had some private family matters for several months now," Boskovic said in a statement released by the club. "It's a difficult decision for me after a very good season here. I think that we will get better and better, but now I must leave. I wish all the best to this team and this club. This city is going to be my heart in the future."
Boskovic was not available for comment at United's season-ending media availability Tuesday, as he was visiting a doctor in Baltimore to have his knee examined.
Boskovic was signed from Austrian club Rapid Vienna in the middle of the 2010 season, and his contract was supposed to run through the middle of 2013. The 32-year-old played in 43 regular season MLS matches over his three years at the club, starting 21 games, scoring one goal and recording seven assists. He only played four games in the 2011 season after suffering a severe knee injury in a U.S. Open Cup game against the New England Revolution.
"It's important that Branko return to Europe to be with his family at this time and thus we are mutually terminating his contract," D.C. United General Manager Dave Kasper said in a club statement. "We thank Branko for all of his efforts with United, including some wonderful performances this year that helped us achieve post-season play. We wish Branko all the best in his future endeavors."