Celtic have suffered a blow following the news Shaun Maloney will face up to four months out after undergoing ankle surgery.
Maloney picked up the injury during his side's 2-2 draw against Inverness at the end of November when his shot was blocked by Ryan Esson.
The news comes as a crushing blow to to the Scotland international, who has struggled with injuries in recent times.
The 27-year-old spent much of last year sidelined by a tendonitis problem followed by niggling injuries.
The loss of such an influential player will cause Hoops boss Neil Lennon a major headache, with his side currently trailing league leaders Rangers by three points.
"He had surgery on Monday," Lennon said.
"It was a simple procedure but he will be out for a length of time. We are looking between three and four and four months.
"It's a huge blow for us and obviously a huge blow for the player. He had a horrendous run of injuries in the previous season.
"It is frustrating obviously because he worked very, very hard to get back to full fitness when he has been out."
Lennon also revealed that Dutch defender Glenn Loovens will be out of action for a month after picking up a medial knee ligament injury during training.