At the start of the season in mid-July, I wrote about Callum McGregor on the back of his bumper new contract.

Just turning 30 years old, a five-year extension was remarkable, although no one was doubting his value to the team as a literal midfield heartbeat, as well as a mature and nurturing captain. The data showed a gentle but perceptible decline in the performance numbers. Yet, the way I reconciled the contract position was to consider the question: “If Celtic did not have Callum McGregor, how much would it cost to go out and buy him from the market?”.

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The answer to that is probably more than the club can afford, even with the recent Annual Report and Accounts showing cash reserves of over £70 million. A declining McGregor is still a vital player to Celtic and of a higher standard than can easily be traded in. And given his role as captain and respected group leader - not to mention the high esteem each manager clearly holds him in - the deal still makes sense in the round.

I write this pre-Atletico Madrid tie, and as I do so, McGregor has the equivalent of 11.91 worth of minutes racked up already this season. So, well over the 10 matches worth necessary for a considered assessment. The question is, therefore, are the ‘decline’ trends continuing? And what does that mean for McGregor and Celtic as the season progresses?

Defensive actions

I’ll start at the back. As the midfield anchor, it has never been McGregor’s role to be a destructive number six like Casemiro or Declan Rice. This season, it has been noticeable the extent to which Matt O’Riley drops into the pivot role with the captain to bolster the central midfield defence.

This may be a subtle general change Brendan Rodgers wants to make in lieu of not having inverted full backs to strengthen the side against counterattacks. There may be a little bit of protecting the captain. An early away match in Aberdeen saw Celtic horribly exposed on the counter with McGregor facing a cavalry charge of opponents.

Let’s start with overall performance action success, and possession won from defensive actions:

The 2022-23 season saw McGregor’s peak defensive performance, especially as 71 per cent of his defensive actions resulted in Celtic winning or maintaining the ball. This has dropped back to 2021-22 levels, whilst overall success in duels and such is at the lowest level since 2020-21. In terms of overall defensive activity volume:

His volume of actions is the highest since the 2018-19 season. Bear in mind, this small sample includes two tough European Champions League ties, plus arguably the hardest run of away matches in the SPFL. Nevertheless, this may hint at a more concentrated role for McGregor although this may smooth downwards over the season.

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What is probably not a good combination is asking him to do more defensive work (volume increasing), whilst the defensive action success rates go down. Regarding pressing data:

The bigger volume of activity is pressing – rushing to close opponents with the ball. This has seen the steepest decline as it is the most physically demanding.  Counter-pressing volumes and success are stable – this is where you press the opponent within five seconds of the ball being lost. This is a much lower volume activity, and therefore easier to maintain performance rates.

Ball progression

There is no doubt Celtic have not been as fluid in their build-up and attacking patterns compared to the dominating attacks seen under Ange Postecoglou. Attacking and creating metrics are likely to be down across the squad – an important context to consider. As regards McGregor, I’ve mapped the ball carry volume with the pack pass completed volume:

The number of ball carries has declined quite significantly, which as well as the context of the season so far, is probably not surprising given his decline in ground speed and agility. The pack passing decline may be a systemic issue across the team as it will reflect positional and attacking coherence as well as opposition strength. Aggressive vertical passing was a key part of Postecoglou’s style of play, and this metric went up for most players under his watch.

Creativity

Looking now at the volume and value of chances created as expressed by number of chances and expected assist (xA) value per 90 minutes:

Of all aspects of play, this has been the most obvious decline curve for McGregor. He simply isn’t getting into the positions higher up the pitch to create good chances for his teammates. Much of this is simply the physical demands of playing in a box-to-box style. It is also why calls for him to be moved into one of the number eight positions to allow e.g. Tomoki Iwata or Odin Thiago Holm to anchor the midfield are probably slightly fanciful at this stage of his career.

The lower quality of chances is simply a function of the fact that given his deeper role and inability to get up and down into the opposition box, any chances he does create tend to be those that lead to e.g. a long-range shot therefore of low value.

Goal threat

The same principles apply to the performance data reflecting the threat McGregor poses to the opposition goal:

This is a steep decline also and his expected goal (xG) numbers are no higher than the normal defenders. Again, to get into scoring positions, never mind running beyond the strikers, is something that as he enters his fourth decade, becomes increasingly difficult.

On-ball value

Finally, StatsBomb’s overall on-ball value metrics aggregate all on-ball activity to provide a single score as to the impact on the team. The higher and more positive the number, the better.

His OBV of 0.24 is slightly higher than last season. In terms of difference to last season, it has seen a decline in his passing OBV by 0.03 whilst defensive action OBV has increased by the same amount. This tallies what we have seen with the broader performance data in that defensive actions have increased (albeit success rates are down) whilst progressive passing is in decline.

Summary

As mentioned many times before, age-related decline is inevitable and largely irreversible without a significant change in role. What we are seeing here with McGregor is as I noted at the start, a gentle but perceptible decline. The aspects of play requiring athleticism and speed such as getting forward to create or score, and pressing, are declining. Declines in agility and strength can be discerned by defensive action success rates.

McGregor’s activities are increasingly focused on defensive aspects and ball progression but from the central areas rather than all over the final third. None of this is to say he should not be in the team nor that his current level of performance is not vital to Celtic. But let’s not ignore reality as some did regarding Scott Brown.

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I hope we see more considered management of McGregor’s time – his withdrawal after 82 minutes at Tynecastle was welcome. Perhaps, occasionally, he can sit one out and the likes of Iwata can be given game time to develop into the role. That is only fair to McGregor and to the team as flogging him game after game will only exacerbate the obvious decline patterns we can see already into this season.