How do the performances of Celtic’s David Turnbull, Callum McGregor and Stephen Welsh compare to last season?

So far this campaign the midfielder has come in for some criticism but has still managed to score three times in seven league games, albeit all three were against St Mirren.

Meanwhile, Callum McGregor was an ever-present figure in the midfield last term with 37 league appearances from a possible 38 and had begun life under Ange Postecoglou in impressive style before injury struck earlier this month.

Further back, central defender Stephen Welsh made his first-team breakthrough in October and ended up featuring 16 times in the Premiership and contributing to eight clean sheets. This season he played regularly and earned some plaudits before dropping to the bench after the recent signing of Cameron Carter-Vickers.

Small sample size it may be, yet comparing the numbers and metrics from last season to those of this league season so far can contextualise what people have seen from these players on the pitch.

Here, The Celtic Way analyses how Turnbull, McGregor and Welsh’s 2021-22 Premiership StatsBomb radars compare to their 2020-21 versions.

How to read radars 

Radars are an excellent way to visualise a player's statistical output.

As StatsBomb explains: 

• The radar boundaries represent the top and bottom five per cent of all statistical production by players in that position across various seasons of data from the top five European leagues: Bundesliga, La Liga, Ligue 1, Premier League and Serie A.
• All of the relevant data points and metrics on our radars are calculated on a per-90-minute basis
• We also adjust a number of the defensive metrics to account for the amount of possession the player's team has
• It’s worth noting that not all of the data points and metrics included on the radars measure the quality of the player or their output

David Turnbull

Using StatsBomb’s attacking midfielder radar we can see Turnbull’s offensive remit so far this season. He has increased the number of shots he takes and the number of touches he gets in the opposition box as well as marginally increasing his xG value.

Under Postecoglou’s system, players are expected to press hard off the ball as well as create opportunities on it and this is reflected in Turnbull’s pressure regains improvement. He has, however, gave up the ball more often so far while his crossing has suffered and his open-play xG assisted value has plummeted.

When considering Turnbull’s midfielder radar, it is notable that his pressures value is around the same as last season though his tackles (possession-adjusted) have increased as have his interceptions, suggesting his marked upturn in work-rate off the ball under Postecoglou. The Scotland international has never been much of a dribbler and that is borne out in both radars, while his deep progressions and xG Buildup values were always impressive but have nonetheless increased enough to move him into the 98th and 99th percentiles respectively.

The contrast in his average heatmap in 20-21 and 21-22 shows the consistency of positioning Postecoglou has given him so far – he generally starts in an advanced centre-left midfield position while last season he was shifted between attacking midfield and right and left centre-midfield.

Callum McGregor

While occupying central areas like last season, the new term has placed even more importance on McGregor’s ability as he embraces the single-pivot position in a high-intensity, pass-heavy system with aplomb.

The captain’s excellence is generally consistent and that is reflected in the traditional StatsBomb midfielder radar. His passing accuracy and xG Assisted values have remained largely the same while his deep progressions have fallen but are still at an indisputably elite level.

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The explanation for the seeming decline in the likes of dribbling, pressure regains and pressures – as well as the improvement in interceptions, tackles and turnovers – can be found in the difference in role McGregor has been asked to play under Postecoglou; it is less attack-focused and is much more about build-up and keeping the team’s passing intensity at a high level.

This is further reflected when considering metrics such as xGBuildup (99th percentile) and carry percentage (94th percentile) as well as defensive signifiers like dispossessed value (up 10 points from the 48th to 58th percentile) and dribbles successfully defended (up from the 80th percentile to the 99th).

Simply put: the captain is essentially sacrificing his own goal-involvement numbers for the benefit of the team’s overall style of play. He has been sorely missed during his recent injury.

Stephen Welsh

Welsh enjoyed a run in the starting XI near the start of the season in which he regularly partnered Carl Starfelt. Within this run he switched sides from right centre-back to left and also notched a goal. In terms of his defensive statistics, however, there are a few points to consider.

What sticks out is his improvement in tackles/dribbles past percentage of  78 (up from 66 last season). That progression has moved Welsh from the 26th percentile to the 75th and, for context, is a better rate so far this season than Rangers centre-back Connor Goldson (73; 55th percentile).

Welsh has also marginally improved his passing percentage and possession-adjusted interceptions while his possession-adjusted tackles value has increased to the point he has jumped from the 73rd percentile to the 98th.

Interestingly given Postecoglou’s system, Welsh’s pressures value has decreased while the number of times he plays a long ball when not under pressure has increased. He rarely, however, takes the long option when pressured. In the air, Welsh’s win rate is around the same although he wins slightly fewer per game.

Perhaps in a further reflection of the way the Celtic manager wants each player to be heavily involved in play, Welsh is this season in the 99th percentile for xGBuildup. Again, a look at the heatmaps between seasons helps illustrate the difference in role Welsh has had to adjust to this season – both in terms of switching sides and the expectation that defenders play their part in build-up play.