Rangers defender Nikola Katic faces a spell on the sidelines after suffering an injury in pre-season training.
The 23-year-old Croatian made 29 appearances for Steven Gerrard's side last season, scoring three goals.
A statement on the club's website read: "Rangers are disappointed to announce that Niko Katic has sustained an injury during pre-season training.
"The injury was sustained more than a week ago and will keep him out of action for the foreseeable future.
"Niko is being looked after by our medical team led by Dr Mark Waller."