Manager Brendan Rodgers confirmed the news today
Celtic midfielder Tom Rogic is to miss around eight weeks of the season after undergoing surgery on an injured ankle.
The Australian picked up the injury in a match against Dundee in December and has been missing from the team since then.
Speaking to the club's official website, Celtic manager Brendan Rodgers said: "The disappointment is that he'll miss up to eight weeks. It’s unfortunate as it came at the end of training at the same spot he had it before. His foot stuck in the ground and he did a full twist on it.
"It was either to go through the same procedure as before or an operation. So he went to London and had an operation and he's on his way recovering now," he added.
The Glasgow side entertain Inverness Caledonian Thistle in the fifth round of the Scottish Cup at the weekend and it's 17 years since the minnows famously stunned the Celtic crowd with a 3-1 win at Parkhead.
The Scottish champions are currently unbeaten in domestic competition this season and have only dropped points once - a 2-2 draw against Inverness last September.