Ronny Deila has claimed that Celtic paid the price for a "sloppy" performance in the 2-2 draw with Kilmarnock on Wednesday evening.
Kilmarnock twice fought back from behind to earn a point at Rugby Park, and Deila refused to offer any excuses for his side's failure to pick up all three points for the first time this season.
"I am disappointed of course," he told reporters. "We should have scored more goals but I am very disappointed that we were sloppy in defence.
"It was like that against Partick Thistle in the second half and we continued that today and we got punished.
"They got four or five chances and that is more than the other teams have had in 10 games. So we deserved to get punished when we don't score goals and are so sloppy."
Celtic return to action against Inverness Caledonian Thistle on Saturday.