ESPN reported that a deal bringing Dempsey to Seattle could be announced as soon as Saturday.
On Thursday, the Sounders announced that midfielder Shalrie Joseph had renegotiated his contract and would no longer hold one of Seattle's three designated player slots. That would open up a spot for Seattle to make another big splash after already adding striker Obafemi Martins earlier this season to pair with Eddie Johnson up front.
Dempsey played in MLS until 2007 when he was sold to Fulham. He joined Tottenham last season and had seven goals in 29 league matches.