Rangers have suffered a major blow ahead of Sunday's Old Firm showdown after playmaker Niko Kranjcar was struck down with a serious knee injury, according to reports.
The Croatian is definitely out of this weekend's Betfred Cup semi-final clash with Celtic at Hampden and could be sidelined for months to come if the injury is as bad as Gers chiefs fear.
Former Portsmouth and Tottenham midfielder Kranjcar damaged knee ligaments in a freak training ground accident on Tuesday.
Ibrox medics are now waiting for the swelling to go down before they are able to fully assess the problem but he could be ruled out for six months or more if the issue turns out to be a ruptured cruciate ligament.
His loss is a huge setback for Light Blues boss Mark Warburton, who has been seeing more from the 32-year-old in recent weeks after a sluggish start to his Glasgow switch.
Kranjcar looked well off the pace when Gers were given a 5-1 pasting in their first derby duel with Brendan Rodgers’ rampant Hoops last month and was hooked at half-time.
But his influence has grown since then, with glimpses of his best form clear in the recent 2-0 win over Partick Thistle after he netted a sensational opener.
Rangers will also be without Kranjcar's former QPR team-mate Joey Barton when they run out at the national stadium to face their old rivals, with the Englishman's Ibrox career effectively over after a fall-out with Warburton.
