Ruiz scored a league-leading 24 goals for the Los Angeles Galaxy in 2002 and was voted league MVP as the Galaxy won the MLS Cup. He tied New England's Taylor Twellman for the 2003 scoring lead with 15 goals.
He then scored 31 goals with Dallas from 2005-08. The 31-year-old has since played with Paraguay's Olimpia, Mexico's Puebla and Aris. He scored three goals this season in the Europa League.
His signing was announced Tuesday.