The U.S. international veteran had spent last season on loan in Spain but is now a free agent after being let out of his deal with the embattled Scottish side.
Bocanegra, who spent last season on loan at Racing Santander in Spain's second division, played a full season for Rangers in 2011-12 after signing a three-year deal with the club following a move from Ligue 1 outfit Saint Etienne. With Rangers forced to drop down to Scotland's fourth tier following extreme financial woes, Bocanegra began play with the club in the depths of Scottish soccer last season and was named team captain prior to securing his loan on the final day of the summer transfer window.
Bocanegra has been heavily linked with a move back to MLS, where he began his professional career as a member of the Chicago Fire in 2000, and he would be subject to the league's allocation order, should he return. Despite being on U.S. manager Jurgen Klinsmann's 35-man provisional roster for the upcoming CONCACAF Gold Cup, he was not selected for the competition. Klinsmann cited his finding a new club as being the top priority.
The 34-year-old Bocanegra, who has 110 caps, has not featured for the USA since last November's friendly with Russia, a match from which he departed in the 18th minute after tearing his hamstring. The U.S. captain was controversially benched for February's World Cup qualifying match against Honduras, and he has not been called back in by Klinsmann since then. Clint Dempsey has taken over as the full-time captain for the USA in Bocanegra's place.