Replacing Ange Postecoglou at Celtic is proving to be a 'nightmare' for Brendan Rodgers, according to Chris Sutton.
The Hoops lost their first Premiership match of the season yesterday as Kilmarnock defeated the champions 2-1 at Rugby Park.
It was the second time this season that Derek McInnes managed to get one up over Rodgers, having previously knocked the holders out of the Viaplay Cup in August.
With Killie's victory secured, in turn, it provided Rangers with a huge shot in the arm as far as the title race is concerned. The gap stands at just five points as the derby between the Glasgow giants looms at the end of the month. Philippe Clement's side also have a game in hand.
Sutton insists a domestic defeat was on the cards for Rodgers for some time, having slipped up against Motherwell just a couple of weeks ago.
And the former Parkhead striker believes the Irishman is struggling with filling the boots of Postecoglou who left for Tottenham in the summer.
He told BBC Radio 5 Live: "This was coming and it's been coming all season. Whether you want to split domestic form up with the Champions League, which I think you can. The Champions League has been a massive disappointment. Celtic weren't ready, they weren't prepared.
"They should have been ready. The';ve known from a long time ago they'd qualified. All the years of going through the qualifying rounds and that stress, this time Celtic were in.
"Brendan Rodgers' issue was following Postecoglou. You see what football he plays at Tottenham. It was fast and furious with Postecoglou. There have been patches - and that's the best way to describe it - there have been patches in games, even in the first half-an-hour against Kilmarnock when Celtic were very good and didn't take their chances.
"There are worrying signs as far as I can see and I don't think the fanbase are fooled by what's going on. The biggest worry at the weekend is that you can lose matches in many ways; you can be outplayed by a team but you can't be outrun or outfought. That's what Kilmarnock did. Celtic seemed to freeze and show a fear. The truth is, domestically, that absolutely shouldn't happen.
"Brendan's talked about bringing more quality in in January. But Celtic have their model; it's a development model and we all understand what that model is because they can't compete with Premier League teams and spend that sort of money.
"For example, this season Sheffield United are bottom of the Premier League and have spent three times more on transfer than Celtic. They can't compete.
"But what I can't work out is how can Celtic bring in players who have been there and done that, but keep it within the boundaries of their particular model? That's the difficulty. It does look like things need freshening up.
"But this has been coming. A lot of performances have papered over the cracks, albeit they only lost their first game in the league this season. It hasn't been as slick or fluid and it's a bit of a nightmare for Brendan that he's following Postecoglou. That's the truth."
