Paul Lambert played his fair share of football under Martin O'Neill during his eight years at Celtic. So, he will know well what it takes to succeed under the Northern Irishman.

Unfortunately for Celtic, O'Neill is struggling for success right now. Celtic have lost three games on the trot. Two of those defeats have come at the hands of the Rangers.

Of course, the life of a manager at Celtic is always results-oriented. So, it should come as no surprise that questions have been raised about O'Neill.

Some of the comments coming out of the weekend certainly created fresh doubt about O'Neill's future managing Celtic.

Cameron Carter-Vickers is one of the players who have been outspoken about the players needing a bit more direction. He said after the defeat to the Rangers:

"We played a bit too random. We need to get better at that, getting a script and sticking to it.

"The last two games we've played have been big pressure games. As players, you rely on having something to fall back on.

"We haven't had the time to get that. As players, we can do better for sure. It's something we can improve on.

"There's a lot of new players at the club. It's about getting everyone on the same script. The group are together like we've always been. We need to find consistency."

Are Carter-Vickers' comments a potential hint at a lack of direction that is coming from the coaching team right now? It sure does sound like that.

Some fans have applauded the openness. Others have not been particularly impressed with Carter-Vickers' take on the matter.

Lambert is someone who firmly falls in that second category. He said on BBC Sport Scotland (via Celtic Shorts):

“The players need to take responsibility. I watched the game and dear oh dear…

“That was cringeworthy, the stuff from Carter-Vickers. I thought ‘hang on, you’re not making a movie.

“Solve the problem yourselves. When something is not going right, you look to rectify it, you don’t look to a manager to say ‘do this or do that’.

“I thought that was bang out of order, coming from someone who’s been a decent player for Celtic.”

It would be safe to say that something is missing at Celtic right now. It might be the players who are falling short of the mark. It might be the coaching team as well. Or perhaps both.

Of course, there is no doubt that the board did fall short of the mark in the summer transfer window, as they allowed the squad to get weakened once again.

They saw key players like Daizen Maeda, Kelechi Ihenacho, Reo Hatate and Arne Engels leave. And one could argue that they did not upgrade in even one of those areas.

So, the results on the pitch should not really come as a surprise to those who have been keeping up with the situation at Celtic for the past few years.

It has been as much of a failure off the pitch as it has been on it. Somehow, the club have continued to win trophies throughout this time. But that does not mean that they have not gotten things constantly wrong.

Unfortunately for Celtic, those mistakes might finally catch up to them. Now, it remains to be seen if they can turn it around. And if they are to do that, both the players and the coaches will need to take their fair share of responsibility.