There can only be one voice in a dressing room. And there can also only ever be one winner in a dressing-room bust-up. The gaffer.

It's a fight, as a player, you simply cannot win. I admitted defeat in that particular battle many times which usually led to me getting the "have boots, will travel" sign out again. I also witnessed other players try and fail by either questioning why they were not playing, the manager's tactics, or his team selection in front of the lads.

If you chose to vent your frustrations in a private one-to-one behind closed doors, the results could maybe not be as terminal. Most managers would take your points on board and tell you why you weren't playing – then not play you the following week anyway!

I, unfortunately, had that chat more than most. But vent your spleen in front of the rest of the players and staff? You are finished.

From the outside looking in, it appears Kenny Miller has done exactly that. I know Kenny well and he has a strong opinion on the game, and how it should be played. He is not scared to speak his mind, which, for me, is a good thing. There is no conceit in him whatsoever. That can go down the wrong way in a dressing room though, and it looks like it has in his case. How else can you possibly explain such a figurehead at the club going from being the first man Pedro turned to just after going 1-0 down in the heat of a derby game, to being binned from the entire squad of 20 players for the Hamilton Accies game?

Not only that, but then being ostracised to train with the under-20s. You just don't do that to an experienced player unless there has been a massive fall-out or he is a player you are trying to get rid of. I have no doubt Kenny was fizzing sitting on the bench watching not only Rangers getting a chasing, but witnessing Carlos Pena play hide and seek for 53 minutes.

He would have felt he should have been starting and felt vindicated when he went on so early for the ineffective Mexican. Maybe he has let that frustration boil over after the game. That, surely, is why he has been told to train with the youth team.

I can remember being at Dundee and being told to train with the youth team for different reasons. It was because I had refused to take a pay cut and they wanted to shift me off the wage bill. It hurt like hell and was embarrassing as an experienced player to have to go and train with the kids. It was clearly designed to sicken you but this is obviously not the case here.

In saying that, there can be no doubt that it will be hurting Kenny right now. This is clearly a personal issue between he and Caixinha.

It's a dramatic fall from grace that can really only be explained by them metaphorically butting heads after that Celtic defeat and Caixinha taking umbrage at something that Kenny has said or intimated. There can be no other reason for bombing a top professional completely from the squad for Hamilton.

I am not for one minute claiming that Kenny should be an automatic first pick every week for Rangers. I don't think he has played well enough this season to merit that, and the majority of Rangers supporters would probably agree at the minute. But he must be in the squad.

In my very first Herald column towards the end of last season I said that Kenny Miller deserved a new deal at Rangers for this season. Not only for his performances on the park, but his influence off the pitch. He is a super guy and a model pro which makes the decision to banish him even more baffling. He finished last season really strongly, scoring goals and deservedly got that deal. But he hasn't looked as sharp this season, often dropping far too deep or wide, which has blunted his influence and goal threat. It may well be that Father Time is finally catching up with him at that level, but he is still good enough to get in a squad of 20 at Rangers. That should not even be in question.

To be honest, there has always been a nagging doubt in my mind about not only just how highly Caixinha actually rated him, but whether it was actually his decision to deal him in for a new contract in the summer.

Caixinha was very quiet when the questions were being asked last season amid Kenny's purple patch and rumours of the player going straight to the board to sort his own deal were rife. There has just been something uneasy about the whole situation and it's finally been brought to a head. Doubts have lingered for me from the get-go that Pedro sees Kenny as a threat. It looks now like he is trying to eliminate that.

Players tend to have loyalty towards a manager who has actually signed them. And vice versa.

When you are signed by a manager you will get plenty of chances to succeed because managers live and die by their recruitment. You will get the patience and time to prove that he was correct in bringing you in. With that comes you wanting to do well for him. Usually the first thing a new manager does is gut the place and bring in his own players for that very reason.

Brendan Rodgers has proven to be an exception to that general rule. You only had to witness how hard a Rangers team with eight players Caixinha had either bought or blooded battled the other night after going a goal down to the Accies.

Daniel Candeias running straight to his gaffer to celebrate showed that bond. It was a telling show of unity. That is why the likes of Pena and Eduardo Herrera will be given every opportunity to come good. That can rankle with players in a similar position already at the club, when you see someone getting chance after chance. I have been on both sides of that and you are certainly at an advantage being onside as one of the gaffer’s buys.

Caixinha is the boss and he is entitled to pick whoever he sees fit. He has already shown he is not to be messed with. Michael O'Halloran would concur with that.

After all, it is the Portuguese's head on the chopping block. He will therefore do what he feels is right for him and the club. As Joey Barton found out, overstepping the mark in the dressing room with a manager means you are done. It now looks likely that Kenny Miller has suffered a similar fate.