The bedrock of any title-winning team starts in defence.

Over the two seasons of former Celtic boss Ange Postecoglou's reign, the Australian won five trophies out of six with his side conceding just 22 league goals in 2021/22 and 34 counters in 2022/23.

It helped that Postecoglou has what every manager craves. A settled defensive back line. Postecoglou has the likes of Josip Juranovic for the most part at right-back and Greg Taylor at left-back as well as the solid central defensive pairing of Cameron Carter-Vickers who held the distinction of never having lost a domestic league game whenever the duo featured in the starting line-up. How current Celtic boss Brendan Rodgers wishes he could have been afforded that kind of luxury all season. In stark contrast to his predecessor Rodgers has been scrambling all season to find any fluidity and solidity as well as a settled back four.

Take the four defenders who finished the game against Kilmarnock at Celtic Park in the 1-1 draw against Kilmarnock on Saturday. Tony Ralston at right-back, Stephen Welsh and Liam Scales in central defence and Alexandro Bernabei at left-back. If any Celtic supporter had predicted that the club would finish any game in this campaign with that quartet in defence they would have been laughed out of the stadium and chased down the length of London Road. Nothing screams indictment of the recruitment process more than this. Nothing.

READ MORE: Cameron Carter-Vickers through the eyes of his former coaches

Ralston rode the crest of a wave under Postecoglou and hit a purple patch. He is steady and reliable and always gives 100 per cent but is destined always to be a squad player.

Scales has had the ultimate renaissance in his Celtic career after looking like he was headed for the exit door in the summer. The Irishman has arguably been one of Celtic's best players this season but the cracks are beginning to appear in his game and he has not looked as assured of himself in recent weeks. Welsh is another great Celtic survivor and a player who has never fully convinced a succession of managers that he is an automatic first-team pick alongside another central defender. He is another who is fully committed to the cause but is that enough now at a club like Celtic to warrant regular game time?

Bernabei is more famous for making headlines off the pitch than he is on it. At £3.75 million his purchase in the grand scheme of things will prove to be a costly mistake for Celtic long term. The recruitment team will have a lot to answer for, specifically in this case. They are those who are more scathing in their criticism of Bernabei and believe that the Argentine should never play again for the club. Bernabei may well possess hidden talent but he has largely kept his defensive talents well hidden up until now and the Celtic faithful have almost had their fill of him.

It is a small wonder that Celtic defensively have been a shambles all season, The champions have conceded 18 league goals to date and have given up seven points from winning positions or concession of late equalisers this season. The latest was David Watson's injury-time header at the weekend.

Yet £7.5 million worth of central defensive talent never featured on Saturday. The burning question on every Celtic supporter's lips is why? This is where Rodgers can share some of the blame here. It is he who has deemed thus far that Welsh is a better player than both Maik Nawrocki and Gustaf Lagerbielke.

The Pole and the Swede have struggled for regular game time at the club largely in part due to the resurgence of Scales. That is understandable but does Rodgers believe that Welsh is better than two defenders whom Celtic shelled out over £7.3 million for? Again if that genuinely is the case then that is a damning indictment of the recruitment process. Rodgers's major complaint could well be that Celtic's first-team squad may be bloated but it is also top-heavy with bang-average players.

Back in December, Rodgers had this to say as to why both Nawrocki and Lagerbielke were being denied precious first-team minutes. He said: "I think it is always personality. I think with the young players coming in there are players ahead of them but what always catches my attention is training. I am out there every day watching training and when I see players train and work with that personality then they will always edge their way closer to my thinking. I have said before our squad is quite big and some players have been ahead of them.

"Unfortunately for the likes of Maik and Gustaf, Liam (Scales) has come into the team and really took his opportunity. It is the one area of the team you don't really want to change too much, especially when both players are fit as it is all about the two players playing.

"For any player, it is all about what they do in training as that is all you can do. You can't get too disappointed. If you are working hard then hopefully those opportunities will come for you."

Celtic Way:

Those quotes were damaging to the pair in the extreme. Rodgers doesn't fancy Lagerbielke that's for sure as he wasn't even in the Kilmarnock matchday squad. The Northern Irishman even put the blockers on a move to Serie A side Lecce in the January transfer window when more injury complications emerged with Carter-Vickers.

Whilst Rodgers might not fancy Lagerbielke, it is also abundantly clear that at this juncture of the title race, he doesn't trust Nawrocki to do a solid defensive shift either. Since then Welsh has leapt ahead of both of the multi-million pound summer signings in the pecking order. It beggars belief, doesn't it?

READ MORE: Liam Scales' amazing journey to Celtic: Mentors on his meteoric rise

The manager has to be trusted whenever he picks the team. So, every time the manager names the Celtic defence and this particular duo is absent then he is effectively telling the supporters that the players already on the club's books are better than £7.3 million worth of supposed talent. One can only wonder about the confidence levels of Nawrocki and Lagerbielke. Yet Rodgers's stance and narrative on this issue have been defiant throughout the campaign which is now teetering on the edge of disaster.

The bottom line is that Celtic simply cannot afford to fritter away £7.3 million on non-contributors. Well, it's £11 million if you add £3.75 million capture Bernabei into the mix. It's all money down the drain that Celtic will be lucky to recoup in any shape or form moving forward. Who then sanctioned the purchases of both players? When Welsh and Scales - who are let's face it hardly Franco Baresi and Paolo Maldini - are keeping you out of the side then serious questions have to be asked. The manager as well as the recruitment team are culpable in all of this.

It's fair to say that Rodgers's teams have been sussed out without much difficulty and have been easy to play through this season on many occasions. Opposition sides have preyed on and exploited Celtic's weaknesses, especially, at the back of the pack As TCW writer Alan Morrison opined on the subject. He said: "Celtic are as easy to play through as measured by opposition pack passing as they ever have been in recent times, but most worryingly more so than the incoherent 2020-21 season.

Teams are creating more chances of better quality pack passes and the number of Celtic defenders taken out of the game is the highest on record. The obvious question is why? Even allowing for the extenuating circumstance of Carter-Vickers being absent for long spells of the campaign the case can't rest for the defence as the Celtic defence has not put forward a decent case all season. The bedrock of any title-winning team is built on a strong defence. Celtic's defence has been anything but strong in terms of keeping the ball out of the net.

That's exactly why Celtic currently trail league leaders Rangers by two points in the Scottish Premiership title race with 12 games to go and now struggling to defend their crown.