New York Red Bulls sporting director Roxburgh admitted he was taken aback by the move even after Dempsey had been linked with a possible shift to the Red Bull Arena.
"There was even talk he was going to go to Everton. That was the thing. I actually thought he would stay in Europe. I thought he would move to Everton, and then the next thing I heard he went to Seattle," said Roxburgh.
"But we were simply made aware that he was somebody that was willing, as we have some other players.
"So he's not the only one. Quite honestly, in this job every day I'm made aware of God knows how many players that are available. The number I hear that want to come to New York is astonishing. How true that is I don't know."