RANGERS have confirmed that Niko Katic will be side-lined for the foreseeable future after picking up a serious injury in training.

It is understood that the Croatian defender sustained cruciate knee damage during pre-season training and it is likely he will be out for at least six months.

Katic could undergo surgery once the damage has been fully assessed by Ibrox medical staff, but it now looks extremely unlikely that the 23-year-old will play any part in the first half of the Scottish Premiership season.

A Rangers statement read: “Rangers are disappointed to announce  that Niko Katic has sustained an injury during preseason 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.”

Ibrox manager Steven Gerrard may now have to explore the transfer market for a replacement defender, with just Connor Goldson, Filip Helander and George Edmundson at his disposal.

Youngster Lewis Mayo could also be drafted in, but with so much weighing on next season it is likely Rangers will bring in defensive cover.

Speaking previously about adding to his squad, Gerrard said: "We've got numerous targets that we want to bring in to strengthen us and help us over the course of next season. Without giving too much information away it's exciting times to be at Rangers.

"I anticipate more signings but I think we have to be patient. It's going to be a different window.

"I don't anticipate us making lots of signings in terms of trying to make the squad bigger. It's more, can we identify players that are going to make the 11 stronger?"

Rangers have already added to their defensive reinforcements with the addition of full-back Calvin Bassey from Leicester City.