Will Celtic actually miss Moritz Jenz after loan transfer exit?

The club has successfully adopted a try-before-you-buy model to transfers for some years. Most notable was Odsonne Edouard, who arrived on loan for a year from Paris Saint-Germain before sealing a record £9million full-time deal.

This season they have, in a way, adopted this model twice. Firstly, Jenz joined from French club FC Lorient for an initial season. Secondly, Celtic took advantage of the Russian war in Ukraine to acquire Oliver Abildgaard from Rubin Kazan on what they termed a ‘season-long deal’.

This approach isn’t loss or risk-free, of course. There will usually still be loan fees involved and a portion, if not all, of a player’s wage will be paid too. Additionally, these players are taking up a squad slot. If the deal does not work out, you are back to putting in the time and effort to fill the need you presumably still have in terms of squad recruitment.

It may well be that Ablildgaard will follow Jenz in not becoming a permanent signing soon enough. Celtic therefore save on all the signing-on and agent fees as well as the cost of a multi-year contract. Try-before-you-buy in action.

But back to Jenz. The permanent signing of Yuki Kobayashi – and his selection in the two most recent games whilst Cameron Carter-Vickers succumbed to injury issues – was perhaps a sign of things to come.

There appears to be a mixed reaction to Jenz’s departure, with many believing he had made a good impression. What exactly will Celtic miss in Jenz?

No shortage of chances

What Jenz cannot claim, unlike many younger players, is that he was never given the opportunity to shine.

Celtic began the season with Carl Starfelt recovering from a hamstring injury received on international duty with Sweden. Stephen Welsh started the season very well at home to Aberdeen and scored in addition to a mature performance. He then immediately got injured.

Meanwhile, Starfelt was being eased back gradually at the same time Carter-Vickers had some niggling injury.

READ MORE: Why Celtic face a very particular problem one year from now

This meant that Jenz was forced into the team and, due to the misfortune of others, became the one constant over the next 18 matches. He missed just two of them.

There were even goals in his opening appearances at Ross County and Kilmarnock, the latter of which was a spectacular overhead volley.

He was also the only centre-back to complete every minute of the Champions League campaign. In short, and probably unexpectedly, Jenz was given quite the extended audition.

He has, however, only completed 38 minutes since November 5 and with Kobayashi now embedded the end was clearly nigh.

Measuring defenders

If you are widely read on football analysis you will know that defending is notoriously difficult to measure. The reasons being:

* Each team plays a different system – in terms of depth, formation, pressing intensity, zonal or man-to-man – and is of different strength relative to the opposition

* We are generally able to measure on-ball actions. Defending is mainly about positioning and the absence of on-ball actions. That is, the best defending is preventative. By being stationed in the right place at the right time, nothing untoward happens. How do we measure what did not happen?

Therefore, judging defenders in relation to other defenders for different teams and in different leagues is very difficult.

However, in collecting data on Celtic players the aim is to be able to compare them to other Celtic players.

Acknowledging that Neil Lennon’s style is quite different to an Ange Postecoglou team from the outset, they nevertheless play the same opponents and display roughly the same elements of dominance and control. For example going back to Ronny Deila, when I started collecting data, the average number of shots each Celtic side attempts rarely changes.

Comparing defenders against their Celtic peers meets the eye test in terms of what we would broadly agree is the correct hierarchy of performance.

In terms of pure defending, this framework measures defensive action success rate and possessions won from defensive actions. Note that these metrics do not include passing, which is by far the most common on-ball action. More on that later.

Here are those metrics plotted for centre-backs since 2014-15, with the current incumbents highlighted:

With the nominal average also highlighted, we can see that Carter-Vickers is up with the best centre-backs of the last eight seasons.

In the middle section are the middle classes, or average performers. Welsh is certainly in this group being safe in possession with a relatively low defensive action success rate mainly driven by aerial duel losses.

Meanwhile, both Starfelt and Jenz trend towards the bottom left of the chart where we find Efe Ambrose and Jack Hendry. This isn’t where you want to be.

Based on defensive actions alone, there is certainly a strong case for not keeping Jenz.

Defensive errors

What constitutes a defensive error is subjective but you have had the same  person (me) making the judgement using the same criteria for eight years. Most commonly it is giving the ball away in dangerous areas, or being out of position or fluffing a clearance or not dealing with a cross. It is something ‘major’ and noticeable as opposed to slight positional errors, for example.

These are rare events – less than one per 90 minutes – but are often impactful in terms of opposition chances.

The gold standard for this is not unexpectedly Shane Duffy, followed by Efe Ambrose and end-of-career Kolo Toure with all near of above one defensive error per 90 minutes.

Despite improvement in the latter half of the 2021-22 season, Starfelt is still above the peer average with 0.62 errors per 90 minutes.

The other current crop are all near the bottom of the error table with Carter-Vickers and Welsh being the safest in this regard.

Jenz himself, despite some high-profile gaffs in Europe, has a low personal error rate overall; 60 per cent of his errors came in Champions League matches.

Ball progression

Central defenders at Celtic are more than just your traditional stopper as the aforementioned Duffy found out. Ball progression, by bringing it out from the back or passing through opposition lines, is key.

The data for this stretches back only to the more recent seasons than all the way back to 2014-15.

What we have here tells us more about team style and manager instruction. The central defenders under Lennon and Rodgers were not expected to progress the ball quite as aggressively as under Postecoglou.

However, given the four Postecoglou centre-backs we can compare them among themselves. Jenz has the most carries per 90 minutes with ball at feet while Starfelt completes the highest volume of packing passes.

Let’s look at total packing score from passes to see how aggressive those passes were.

As we can see, despite completing the most pack passes, Starfelt’s are relatively safe in that they do not take many opponents out of the game. His pack passing score is even lower than centre-backs playing under a much less aggressively vertical style of manager.

Jenz and Welsh’s numbers are very similar but both are behind Carter-Vickers who averages the highest pack passing score per 90 minutes. For example, if your forward pass just takes out the striker and advanced midfielder, that is worth fewer points than if your pass took out the striker and three midfielders.

Summary

In many aspects of play, especially ball progression, Jenz had a case to be a top pick under Postecoglou. He is also relatively error-free, albeit the more difficult the opponent the more he tends to commit mistakes.

However, his base defending capabilities mean he is probably no better than what Celtic already had in Welsh. Celtic’s commercial decision, then, is whether to spend around £3million or £4 million and the commensurate wages on a new player or stick with a homegrown, cheaper one instead. Purely on that basis, the Jenz decision makes sense.

One final point. If you would like a life lesson from me (you do not) it would be this: find someone who loves you like Postecoglou loves Starfelt and don’t let them go…