Freddy Adu is set to complete his move to Brazilian club Bahia in exchange for veteran Kleberson.
"It's a complicated deal," Union head coach John Hackworth said. "But ultimately we're going to get Kleberson here, they're going to get Adu and we're not going to be able to recover salary cap space in that.
"From Europe to Asia to Australia to South America to Mexico, there was interest in Freddy Ady. He's the type of player and has the type of name that I think attracts that interest no matter what. Finding that situation that worked out for both parties has been much more difficult."