John Kennedy is frustrated Celtic didn't show up on derby day after arriving in great form as his side were dumped out of the Scottish Cup by Rangers.
Steven Gerrard's men dispatched the Celts with a 2-0 win over their rivals thanks to a Steven Davis bicycle kick and an own goal from Jonjoe Kenny.
The Parkhead interim boss was confident his side could get the better of the Light Blues in the build-up to the game as he claimed Celtic were, on their day, the best team in the country.
But it was Rangers who came out on top once again and Kennedy was irked at Celtic's sub par first half performance and the string of chances they squandered, none bigger than Odsonne Edouard's penalty miss.
He told Premier Sports: "I thought the first half we were too passive. We were too soft and allowed Rangers to pass where ever they wanted.
"I said players at half time I thought they lacked a little belief. We were just passing it for the sake of passing. I thought in the second half we responded well, on the front foot that's when we're at our best. We created chances and asked the questions to try and make it 2-1, but we weren't clinical enough.
"In front of goal, we probably didn't have enough belief when the ball falls to you for a first time finish, whatever it might be.
"When it stays 2-0, you've got a mountain to climb. I'm bitterly disappointed how we approached the first half. The second half was better, but this game was all about the result and nothing else.
"You can't give cheap goals away and we need to be clinical at the other end. At Ibrox, you might not create a lot of chances so when you do get them, you need to be decisive. That's where Rangers have been better than us for most of the season."
Kennedy refused to point any fingers and says they will take the result on the chin together.
He added: "We do it collectively, we don't isolate anyone. It's not for a lack of drive, we're working and trying our best. Ultimately, when confidence isn't as high it can impact decision-making and performance.
"I thought we were in a good position heading into this game, playing well and got our belief back, but there was little glimpses in the first half where we lacked that belief. We have to get over that and more character in terms of posing our style on the game."
Celtic will be without a piece of silverware for the first time in a decade.
Kennedy admits it hurts, but vows Celtic will finish the season on a high despite not having anything to play for.
He said: "Of course it is (disappointing), that's what Celtic are all about. We have been very dominant and when you don't, it hurts.
"We represent Celtic every time we play so in terms of how we approach each game from now on, regardless with what's at stake, you have to go out and represent the club. "
