Veteran defensive back Marlin Jackson left practice Tuesday with a ruptured Achilles tendon in his right leg, the Philadelphia Eagles announced, leaving the team even thinner at free safety.
The Eagles didn't provide a timeline for Jackson's return, but it's likely a season-ending injury.
Jackson, who signed a two-year contract with the Eagles as a free agent, is coming off two season-ending knee injuries he sustained with the Indianapolis Colts. He missed the second half of 2008 with a torn anterior cruciate ligament in his right knee and returned in 2009 before tearing the ACL in his left knee during a November practice.
Since letting Brian Dawkins leave for the Denver Broncos in free agency last year, the Eagles have had issues at free safety. They tried second-year pro Quintin Demps, rookie Victor Harris and veteran Sean Jones at that position in 2009.
The Associated Press contributed to this report.