Alvaro Fernandez will play a second stint in Seattle after signing with the Sounders on Thursday.
The midfielder, known as "Flaco," previously played with the MLS club from 2011-12, before he was traded to the Chicago Fire.
Fernandez, 30, has played in his native Uruguay, Qatar and Argentina in recent years but now returns to the team where he scored 13 goals in 55 MLS games.
The move comes a day after the Sounders signed another Uruguayan, Nicolas Lodeiro, as a designated player on Wednesday.
- Seattle Sounders FC (@SoundersFC) July 28, 2016
"It's always great to bring back members of the Sounders family, and Alvaro is a player who knows the organization very well and can instantly come in and contribute to this team," Sounders general manager Garth Lagerwey said in a statement.
"Paired with yesterday's signing of Nicolas Lodeiro, we think we've added two players who immediately make our team better on the field."
Fernandez said he helped sell Lodeiro on the Sounders in recent months.
"I gave strong recommendations to him," Fernandez told the club's website. "That it's an excellent club, the fans are amazing, it's a great organization.
"I recommended that he should come and we would have a good time here."