Mwanga, the No. 1 overall pick in the 2010 MLS Super Draft, is a local favorite, having played at Portland's Jefferson High School before going to Oregon State. He played as a youngster for the Timbers' Alliance club, the Westside Timbers.
Mwanga, a native of the Congo, has 12 goals and nine assists over three seasons and 63 appearances for the Union.
Perlaza, who is from Colombia, joined the Timbers in their inaugural MLS season and has six goals and two assists in 41 appearances.
Copyright 2012 by The Associated Press
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