Celtic's Simunovic ruled out for up to four months
The centre-back will miss the Europa League group stage and return in the new year.
Celtic have been dealt a blow after Jozo Simunovic was ruled out for "three to four months" following surgery on a knee injury.
Simunovic hasn't played since the 2-0 win over AIK in late August and had seen a specialist about the problem.
He has now undergone a "clean-up" operation but faces a long period of rehabilitation that will keep him sidelined through domestic games and the remainder of Celtic's Europa league group stage games.
"We're probably looking at three to four months," Celtic manager Neil Lennon said. "It was a clean-up.
"He knows what he has to do for his rehab and we're discussing if he can maybe go away for a few weeks and do some rehab at home.
"He's doing well. It was a blow for us and a blow for the player but he felt it was a necessity. Thankfully it's not a micro-fracture again, which is a serious operation that would put him out for six to eight months.
"He's had a clean-up and obviously we have to tread carefully with his rehab.
"But the sooner we get him back, the better."