Mwanga moved to the United States in 2006 and attended high school in Portland before playing at Oregon State for a year. The 20-year-old was drafted first overall in the 2010 MLS SuperDraft, becoming the Union's first ever draft selection.
The Union were in pursuit of Perlaza before the 2011 season, but the Colombian striker was claimed by the Timbers and signed by Portland shortly thereafter. Perlaza joined a long list of Colombians who have played for the Union, including current captain Carlos Valdes.
Word of the trade was originally broken by Portland's Owner, and President, Merrit Paulson, who tweeted earlier that the Timbers would "be announcing a pretty significant trade shortly. more on that later."
Steven Goff, the man behind the Washington Post's Soccer Insider, said over Twitter that he heard that the Union were in play to be a part of the upcoming Timbers trade.
Mao Football then speculated that Portland may send Jorge Perlaza away as part of any deal, given that the Colombian striker was held out of practice yesterday. The Brotherly Game heard that the deal would be Perlaza for Mwanga shortly before the trade was officially announced by the Union.