Lustig blow for Hoops
Celtic defender Mikael Lustig faces four months on the sidelines after undergoing a double hip operation.
Manager Neil Lennon revealed the Sweden right-back had been playing through the pain barrier for several months.
With his country failing to reach the World Cup finals and Celtic out of the Champions League, the decision was taken to undergo surgery.
The 27-year-old has been in impressive form for Celtic but Lennon revealed he had been hampered by the problem.
Lennon said: "Lustig had surgery, four months. He had both hips done, so the procedure was a bit more in-depth than first thought.
"We are hoping he will be back March/April time but he had a lot of work done which makes his recent performances even more remarkable.
"His movement was restricted and he was in a lot of pain after games so it needed doing. So hopefully he will come back an even better player which will be brilliant for us."
Also missing from the Hoops squad for the Scottish Premiership clash against Hearts at home on Saturday will be Charlie Mulgrew (groin), Dirk Boerrigter (hamstring) and Dylan McGeouch (knock).
James Forrest trained after recovering from a hamstring complaint as did Tom Rogic, who had been out with a calf injury while Beram Kayal (foot) and Steven Mouyokolo (Achilles) remain out.
Gary Locke's Hearts squad is once again stretched to the limits.
The administration-hit Gorgie club - barred from signing new players - have lost striker Gary Oliver to a leg injury and he joins Ryan Stevenson (hamstring), back-up goalkeeper Mark Ridgers (knee) and midfielder Jason Holt (foot) on the sidelines.
To add to Locke's woes, midfielders Jamie Walker and Scott Robinson are rated as doubtful.
Brad McKay insists he would rather have been on the pitch than in the dugout when Celtic gave his Hearts team-mates the run-around in their Scottish Cup clash at Tynecastle at the start of the month.
The 20-year-old sat on the bench as the Hoops raced into a 5-0 interval lead to kill off any Gorgie hopes of cup glory.
McKay was asked by boss Locke to go on at the start of the second half to help stem the tide and was partially successful as the game ended 7-0 for the rampant visitors.
He said: "Obviously you don't want to be getting beat but you don't want to sit aside and see your team getting beat like that.
"You wish you could do something about it, you wish you were on there, helping the boys and talking to them, organising them, which I like to do.
"I would never sit aside and say I wish I wasn't playing or glad that I wasn't playing. Never.
"The game was over when I got on, 5-0 at half-time is never great.
"Celtic were playing some unbelievable stuff and I was on the bench watching it, puffing my cheeks wondering what was happening.
"I came on and was told first and foremost to defend. We had tried to have a go at Celtic and it wasn't the right thing to do, the way they were playing.
"They exploited gaps and punished us.
"The second half was a wee bit easier because we sat in and soaked up the pressure and conceded a penalty and an unlucky deflection.
"If we had done that in the first half, maybe it wouldn't have been so bad."