When Brendan Rodgers returned to Celtic Park earlier this year, many felt some key players would benefit from the invincible treble-winning manager’s arrival more than others.

One of those was right-back Alistair Johnston. Profiling as a more traditional full-back, comparisons were made about how the Canadian international could perform a similar role to that of Mikel Lustig in Rodgers’ first Celtic side.

Although still a bit early to make definitive judgements, Johnston’s 90-plus minutes in Celtic’s dramatic late win over Motherwell at the weekend took the former Montreal man to over 400 league minutes this season.

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This gives an opportunity to take an early look at how the January signing has performed under his new manager and how this compares to his first few months in Glasgow under previous boss Ange Postecoglou last season.

Defending

Let’s take a look at Johnston’s defensive contribution first. One thing that was immediately noticeable about Johnston following his arrival was that he rarely shirks his defensive duties. Honed whilst playing hockey in his youth, Johnston’s combative style helped him quickly acclimatise to the rough-and-tumble nature of Scottish football.

The first StatsBomb radar, shown below, indicates Johnston has been even more active defensively this season compared to last.  

His Aerial Wins, Ball Recoveries and Pressures/Counterpressures are all up this season compared to last. There is of course some context here, given Celtic have had more away games, one a derby and one when they went down to ten men - in their opening seven league fixtures. Add in the uncertainty caused by selection issues at the back - particularly in the middle of defence – and an uptick in defensive work is to be expected.

Johnston does show signs of improvement in his defensive efficiency though. His Aerial Win% is up slightly while his Tack/Dribbled Past%, the percentage of time a player makes a tackle when going into a duel versus getting dribbled past, is even better than last season and amongst the best in the league for a full-back. His increase in PAdj Tackles and decrease in PAdj Interceptions may also be a by-product of Celtic’s start to the season where they have been made to defend deeper.

As mentioned, Johnston’s pressing volume metrics are also up, consistent with Celtic’s overall increase in pressing so far this season (136 per 90, compared to an average of 111 per 90 last season). Despite an increase in volume though, Johnston hasn’t been as effective in terms of winning the ball back through his pressing. His Counterpressure Regains are only slightly up, while his Pressure Regains are slightly down.    

Possession

Generally picking up where he left off defensively - with some changes here and there - some of which are a result of the team’s start to the season more than individual performance, let’s see how Johnston has performed in possession.

Here we can start to see some interesting changes in Johnston’s tendencies on the ball.

Johnston has not been as involved in possession in general with drops in his number of Open Play Passes and Deep Progressions. He is also carrying the ball less. Again, this can be attributed to Celtic being on the ball slightly less so far this season, given the fixtures list and circumstances within certain games.

However - although on the ball less - Johnston has been significantly more productive in terms of Through-balls and Successful Crosses. There is a similar picture in other possession metrics with almost ten fewer Open Play Final Third Passes, yet Johnston is still producing a similar, even slightly increased, number of Open Play Passes Into Box.

This indicates a more direct style while in possession, as well as an increased responsibility when it comes to chance creation compared to the system under Postecoglou.

Attacking

So how exactly has this change in possession manifested when it comes to actual attacking output?

On the surface - with no league goals or assists in his five league games - it would be easy to say not much. A look at Johnston’s underlying attacking numbers shows signs of a sizeable increase in his expected attacking output though.

He has produced almost twice as many Open Play Key Passes per 90 so far this season, which has resulted in a similar increase in his xG Assisted. Given the quality of chance created so far, Johnston could reasonably have expected to register at least one assist to his name this season.

The above scatter graph further emphasises this. Johnston is currently averaging more Open Play Key Passes than any other Celtic player (min 300 minutes played), while only Kyogo is generating a higher quality of chances for his teammates than the Canadian.

The above Key Passes and Assists graphic from StatsBomb maps these chances. It also shows that, in just five games, he has produced a total of nine key passes which have resulted in an average xG per shot of 0.11.

Role in system

Having looked at his data, it is worth returning to those suggested Lustig comparisons to put Johnston’s early season performances in the wider context of how Rodgers is setting his side up.

What is notable in this regard is that there perhaps hasn’t been quite the change in the system under Rodgers that many expected. In his first spell in charge, Rodgers had Lustig tucking in to make a back three when Celtic had the ball, allowing Kieran Tierney to bomb forward on the left as almost a winger. Given Johnston’s strengths defensively, the comparisons made perfect sense. However, current first-choice left-back Greg Taylor is far from suited to a Tierney-type role.

This has resulted in Celtic so far still very much resembling a 2-3-5 in possession with both full-backs fairly narrow, as the game at the weekend showed. There have been small tweaks here and there but Greg Taylor - who struggled in the opening weeks - has been noticeably narrower again in recent weeks, inverting similarly as he did under Postecoglou, though perhaps still not as aggressively as before, admittedly. 

Johnston has never been quite as adept as Taylor at inverting, and he is probably slightly wider in the above pass network compared to the Scottish international. Ultimately though, he appears to be getting on the ball in similar positions as he did last season, too.

What is noticeably different though, and what the data for Johnston shows - and to a lesser degree Taylor - is that the full-backs have had a heavier involvement in terms of chance creation in the opening weeks of the league campaign, particularly compared to Celtic’s wingers for example.

Conclusion

Johnston has enjoyed a steady, if unspectacular start to the season. Some of this could be attributed to missing pre-season and the first few league games through injury, of course. There were certainly moments in his first few games back when he was visibly struggling, so he may well still not be back up to absolute full speed.

That said, even though he is taking up similar positions in a system that appears on the surface similar, by digging into his data (again a small sample size) we can already see some interesting changes in his role under Rodgers in these early matches.

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The primary one is his increased responsibility in terms of chance creation. In that regard - like Celtic in general - you get the feeling there is likely more to come as the team becomes more accustomed to the tweaks Rodgers is implementing.