McDonald, 27, started the first nine regular season matches this season but subpar performances relegated him to the bench. He made just three league appearances in the past two months and did not accompany the squad on a recent western swing to Seattle and Colorado.
His final appearance came last Friday in the second half of a friendly with Chivas Guadalajara at RFK Stadium. He played in defensive midfield, not on the backline.
Ethan White, Daniel Woolard and Conor Shanosky had jumped in front of him on the depth chart for central defense, and with Dejan Jakovic returning from injury last week, his outlook for playing time grew dimmer.
With a base salary of $235,000, McDonald was fourth on United’s payroll. A portion of his contract will remain on D.C.’s books, club officials confirmed. In the trade, United received a 2014 third-round pick (which is actually a first-round selection in MLS’s supplemental draft) and a pick the following year depending on how much he plays for Real Salt Lake.
United acquired McDonald in June 2011 from San Jose for allocation money. He made 63 regular season appearances (62 starts) and added three goals and five assists.
McDonald and Jakovic anchored a 2012 defensive effort that propelled United to the third-best record in the league and a berth in the Eastern Conference finals. However, neither has met expectations this year and have shuffled in and out of the lineup as United (2-13-4) has endured the worst season in its history.
With several backline injuries, Real was actively seeking defensive reinforcement. The Utah club leads the Western Conference with an 11-5-4 record.