Neil Lennon warned his Celtic players to ignore the prospect of Champions League glory for now to concentrate on domestic duties.
A 1-0 home defeat by Inverness on Saturday meant the Hoops have dropped 17 points from 14 Clydesdale Bank Premier League games, only four less than they did in the whole of last season.
One theory for their lacklustre display is that the Parkhead players are thinking too much about the Champions League Group G decider with Spartak Moscow on December 5.
However, boss Lennon, who threatened to quit following an altercation with angry fans during the game in which Billy McKay grabbed a second-half winner for the visitors, said: "Well, if it is then they'll not play.
"I'm fed up talking about Champions League games when we are playing domestic games.
"I know it's all new to them, and I know there is a big game looming on the horizon.
"But I can't accept players thinking that way, because they won't play.
"They can't waste games, they can't think of other games when they're playing against decent SPL teams, which Inverness are."
To somewhat contradict his manager's desire to get his players focusing on the home front, skipper Scott Brown revealed he will delay surgery on an ongoing hip problem in order to play against Spartak in a game which promises a place in the last-16 of the competition for Celtic if they get a better result than Benfica manage in Barcelona.
The Scotland midfielder, 27, who came on as a second-half substitute against Caley, said: "I feel not too bad just now and hopefully that continues.
"The aim just now is to play against Spartak and we will see how it goes.
"I will just need to calm down on the training pitch and hopefully play as much as I can in the games without any pain.
"After I get the operation I should be fine.
"However long I play and whatever operation I get I will still be out for the same time.
"If I can prolong playing until we see what happens in the Champions League, hopefully it will help me and help the club as well. But the decision was fully mine.
"The gaffer asked if I wanted to go for the surgery but I said I would rather prolong it and try to play in the Spartak game. He was delighted about that."
Terry Butcher was delighted to win at Celtic Park for the first time as a manager on the day Caley recorded their first league win in the east end of Glasgow to move fifth place in the table.
The former Rangers defender, however, insists the Hoops, who lead Aberdeen by one point albeit with a game in hand, will retain their title.
He said: "For me they are going to win the league, there is no doubt about that because they have the resources.
"They have one eye on the Champions League which is understandable, but I don't see them letting the title slip at all, I think they will kick into gear just after Christmas and New Year."
While the debate surrounding the reconstruction of Scottish football continues, with the SPL and Scottish Football League both formulating proposals, Butcher declared himself happy with the status quo
"I think it is a great league," he said. "We are talking about reconstruction but it is one of the best competitions for a long, long time.
"I can't remember enjoying it as much. I know we are doing pretty well but the standard of football, the passing; I think it is a great environment for young players to blossom in.
"They are going to change it, they are going to do this and that and I am not happy with that.
"My chairman won't be happy with me saying that but we are giving youngsters a real chance to grow on the SPL stage and enjoy it."