Sardinas (back) sustained an ankle injury during his rehab assignment at Triple-A Norfolk, Roch Kubatko of MASN Sports reports.
Sardinas, who has been on the disabled list since the end of April with the back injury, began his rehab stint last week only to suffer the ankle injury. The severity of the ankle issue and whether the back injury still a problem remains unclear, and the 25-year-old currently has no timetable for his return.