Celtic captain Scott Brown is facing up to three months out with a knee injury.

Brown only returned to action after a four-week absence for the goalless draw at home to Kilmarnock at the weekend but was injured late in the game and a scan showed he had suffered ligament damage.

Ahead of the crucial Europa League clash with Ajax at Parkhead on Thursday night, manager Ronny Deila revealed the Scotland captain could be sidelined for up to three months.

"We don't know for sure yet," said Deila. "But it could be eight to 12 weeks."

It was not immediately clear if the midfielder would require surgery.

"We don't know if he needs an operation but we hope that is not necessary," Deila added.