The 31-year old Costa Rican forward was picked up by the Lions in the MLS Expansion Draft last month but they have opted to send him to DC to open up another foreign player position.
"The additional international spot gives us some increased flexibility to finalize the squad heading into our inaugural 2015 campaign," said Orlando City head coach Adrian Heath in a statement.
Former Deportivo Saprissa ace Arrieta scored 18 goals over three seasons with Columbus Crew and will bring plenty of creativity to the forward third at the RFK Stadium according to general manager Dave Kasper.
"Jairo ?will provide us with important depth this year at the forward position," Kasper said in a statement.
"He is a smart player who finds great spots on the field, and we like his work ethic and commitment. We welcome him to the DC United family."
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