Kris Boyd has claimed "something's not right at Celtic" but he's not certain of the problem.
The former Rangers striker reckons things are in such a state at Celtic that matters could "spiral completely out of control" unless corrected quickly.
That's not to say Boyd hasn't been impressed by Brendan Rodgers' side in spells this season, rather that a few issues have cropped up.
The Sky Sports pundit cited an "SOS to the Green Brigade" with the group set to return to Celtic Park for the match against Livingston this weekend.
Defeats to Kilmarnock and Hearts led to chants against the board and Peter Lawwell and "brought a cloud of gloom" over Parkhead.
But Boyd insists there really ought not to be issues at Celtic given the club remain top of the league table and recently enjoyed a Champions League win.
Despite the positives, Boyd reckons there is an unavoidable discontent at Celtic which could cause serious problems unless the tide is turned.
In his Scottish Sun column, Boyd wrote: "Things have got so bad they’ve even sent an SOS to the Green Brigade to return. What a U-turn that is — and they better start to behave.
"Something’s just not right at the moment. I can’t quite put my finger on it, but they need to arrest it before things spiral completely out of control.
"There really shouldn’t be any problems in Paradise. After all, they’re the reigning Premiership champions and Treble winners — although they’ve lost one of them — and are still two points clear at the top.
"Earlier this month, they celebrated a first Champions League home win in a decade.
"There have been times this season when they’ve pressed the pedal and produced some fine displays.
"But those back-to-back defeats to Kilmarnock and Hearts have brought a cloud of gloom over the place."
And Boyd was surprised to see Rodgers being so critical of his players after defeat to Hearts - but reckons the mind games have started with his comments.
"I don’t think I’ve ever heard Rodgers criticise a group of players like this," he added.
"He was the man who would cuddle you and make you believe he would make you a better human being.
"I don’t know what’s going on but the dynamic has changed.
"The majority of the Celtic squad have been miles off it — and I include Rodgers in that.
"Rodgers is an intelligent man who knows what he’s saying. The mind games have already started.
"This weekend's home clash against rock-bottom Livingston could lift spirits just in time for Christmas.
"But I’m not sure it’ll get all of them off Santa’s naughty list."
