A disappointed Ronny Deila admitted his frustration after Celtic's 0-0 draw with Ross County on Saturday afternoon.
Dundee United lost 2-1 on the same day, meaning the Hoops actually extended their lead at the top of the SPL, although Aberdeen are yet to play (they travel to Inverness tomorrow).
But Deila was unhappy with Celtic's flat performance during a torturous 90 minutes in which they barely threatened County at all.
"It was a very frustrating game," the Celtic boss told reporters after the 0-0 draw with Ross County.
"We had the ball for 90 minutes but didn’t manage to break them down and get the tempo up. With so much possession, we need to create more and that’s what’s disappointing today.
"It’s learning to deal with teams like this but it’s not the last time we’re going to meet a side that will sit in.
"I understand the fans' frustration. I am frustrated too. We have created a lot of chances this year but this time we didn’t manage to score. That’s the disappointing part."