Celtic manager Neil Lennon has admitted that club captain Scott Brown may need to undergo surgery on his hip.
The 27-year-old midfielder started the Scottish giants' Champions League clash against Benfica in Lisbon on Tuesday, but was substituted after 64 minutes.
"I think Scott Brown has run his course and we may have to book him in for surgery," said Lennon. "We are looking at eight to 10 weeks. He has been pushing himself to the very limit."
"We can't keep asking him to put himself through the amount of distress that he is obviously feeling towards the end of his time on the pitch.
"He has been a huge player for us this season, but I think it is time now that he needs to get the problem addressed and, hopefully, he will having something to look forward to in the New Year."
Celtic lost 2-1 to Benfica and are now third in Group G with seven points from five matches.
Germany
Switzerland
Hungary
Scotland
Spain
Italy
Croatia
Albania
England
Denmark
Slovenia
Serbia
Austria
France
Netherlands
Poland
Romania
Belgium
Slovakia
Ukraine
Portugal
Turkey
Georgia
Czech Republic