Carter-Vickers suffered an Achilles injury playing for the Scottish champions in the Europa League match against Sturm Graz at Parkhead last month and has since undergone an operation.

But caretaker O’Neill, who will be in the dugout at the SMiSA Stadium in Paisley tonight when the Glasgow club return to William Hill Premiership action against St Mirren, has admitted the defender will be sidelined for longer than medical staff had originally anticipated.

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The 19-times capped 27-year-old had hoped to feature for his country in the World Cup finals in Canada, Mexico and the United States in June but the Northern Irishman is unsure if his player will be fit in time.

Elsewhere, the Celtic interim manager has also stated that Callum Osmand, the young Welsh forward who netted in the Premier Sports Cup semi-final win over Rangers at Hampden earlier this month before suffering a hamstring injury in a Europa League game against Midtjylland in Norway, will also be out for longer than expected.

Celtic interim manager Martin O’Neill (Image: Stuart Wallace / Shutterstock)

Asked how long Carter-Vickers would be unavailable, he said, “The whole season. Funnily enough, I did ask him yesterday, did he think he would be ready for the World Cup? He said he thought that would be very doubtful. Yeah, we will not see him. I think it might be April before he’s even on grass.” 

O’Neill continued, “James Forrest is still missing. Kelechi Iheanacho has done some work, but wouldn’t be ready for this (the St Mirren game). With Alistair Johnston, it’ll be four or five months. 

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“Although they had the same operation on the same day, Callum Osmand was worse, believe it or not. He’ll be five months. Obviously Jota is out now. I’ll not see him. I’ll certainly not see any of those boys.”

The 73-year-old, though, was able to provide Celtic supporters with a positive update on Uruguayan left-back Marcelo Saracchi ahead of another big week for the Glasgow club.

“He will also be out, but he’s getting close again,” he said. “I’m hoping that some of these lads, if they don’t make the Feyenoord game, would at least be available for selection for the Hibs game. Which might not bother me – or it might.”