Callum McGregor has admitted Celtic are at a "crossroads" after being dumped out the Viaplay Cup.
The Celtic captain made the admission as he compared the current situation to that when Ange Postecoglou had come in two seasons previous.
But McGregor refused to use excuses for the defeat as he branded the defeat a "reminder" of the challenge to win a treble - or any given match.
On Celtic TV, McGregor said: “Not good enough.
“Celtic teams have to play with a certain level of personality and quality and we didn’t do that.
“But it’s a reminder to everyone that you don’t just have the God-given right to turn up and win trebles. It’s not easy.
“You come here and have to fight and find a way to win the game and we didn’t do that.
“We didn’t have enough quality so that’s disappointing for sure. But we have to learn from it now.
“We’re at a crossroads now in the season, similar to maybe where we were two years ago when the new manager came in.
“It’s important everyone sticks together, we find the solutions, we find the answers to the problems that lie on the pitch.
“And it serves as a reminder that every time you cross the line you have to give everything.”
Brendan Rodgers did suggest the artificial surface at Rugby Park had been a factor after the match.
"The pitch. The pitch. There’s nothing else," he said when asked what makes away matches against Kilmarnock so difficult. "You look to move the ball quickly and obviously when you are playing against an opponent who are strong, quick, and can run, you need the ball to be able to move fast and clearly it wasn’t for us today.
"Still, I don’t want to make any excuses. It’s been a tough place to come. As I said, today we didn’t do enough."
