Celtic manager Neil Lennon slammed his players for being distracted by their forthcoming Champions League fixtures after his side slumped to their first defeat of the season when they lost 2-1 away to St Johnstone on Saturday.
The result leaves Celtic, who open their Champions League campaign against Benfica at Parkhead on Wednesday. with just two wins from their opening five Scottish Premier League matches.
An angry Lennon said he has now banned all talk of Europe as he aims to stop their stuttering start to the season.
"If I hear the Champions League mentioned one more time I will scream and I have told the players that," the Celtic manager said.
"Some players never turned up against St Johnstone and I think some players believe their own hype. Some are not concentrating on what they should be doing and thinking about the Champions League.
"They have to get it out their heads and concentrate on these games when they come.
"I think some of them are away in the clouds at the moment thinking about these big games coming up and not what they should be doing and that is winning games in this division.
"I am not going to answer any more questions on the Champions League before a SPL game as I think it is festering down to the players.
"They look like they have taken their eye off the ball today in a big way.
"Maybe it is a new experience for them but they have to buck up their ideas at some point.
"It was maybe not complacency out there but it certainly wasn't the quality I expect from these players and there were far too many off form.
"Maybe the international break came at a bad time with so many players going away but we played like strangers at times and we conceded two poor goals."
At McDiarmid Park, Kris Commons had given the Hoops a perfect start when he fired them into a fourth minute lead with a fierce strike from 20 yards before Rowan Vine set up Gregory Tade to rifle home an 18th minute equaliser.
Vine then curled a stunning shot past Fraser Forster to put St Johnstone in front ten minutes from time and the Hoops couldn't recover to rescue a point against a side who had been forced to cancel training on Thursday after seven members of the squad were hit with a virus.
The result comes on the back of a 2-2 draw with Hibernian in their last match and Lennon says their league form has been unacceptable.
"One point from our last two league games is unacceptable and that performance was not acceptable no matter what the circumstances are," he said.
"We got off to a great start but never capitalised on it and to be honest we never looked like capitalising on it either.
"People might say we deserved to lose but we didn't play anywhere near well enough and we didn't pass the ball well enough and we didn't compete.
"We probably thought after we scored it was going to be easy but games are never easy.
"What I detected was a listlessness from us at times. There was no real urgency about our play. We did create some chances but again we were not sharp enough to finish them off and defensively at times we looked poor.
"We were not committed enough to challenges and out of position.
"They will be all right for Wednesday and up for it but that's the wrong attitude to take, they should be up for these matches as well.
"It will be a full house on Wednesday and I'm expecting a big performance from them.
"Today's performance was needless and I am very disappointed for the first time in a long time with them."