January Scouting Reports- Centre-Backs
Identifying coherent transfer targets for Celtic with data and video analysis.
For this peer group, I conducted data searches for U25 Centre-Backs who excel in key metrics (Pass Completion %, Progressives Passes, Progressive Carries, Defensive Duels Won%, Interceptions, Aerial Duels Won, and Aerial Duel Win %, and Ball Recoveries).
In my previous Scouting Report on Centre-Forwards, I defined and outlined my methodology in further detail. The link is here if you wish to know how I gathered the scores for each player in the data set:
Centre-Backs
The bar chart above is a holistic view of thirty Centre-backs in the peer group I constructed. The bars represent their Robust Z-Scores normalized to the max value of 1: Gael Alonso, Oleksandr Romanchuk, and Liam Scales score in the high tier. Taras Mykhavko is a terrific left-footed centre-back in the 2nd tier, but with Celtic’s unwillingness to spend a high fee in January and the lack of necessity for a left centre-back, I will not analyze him any further— though he’s one Celtic could look at in the Summer to replace Scales or Trusty. In the third tier, there are a few names I like who could be realistic targets for Celtic: Eivind Helland, Tino Jukic, and Rufai Mohammed. In this article, I am going to focus on the top three scorers: Gael Alonso, Oleksandr Romanchuk, and Eivind Helland, with the rest being put aside on a B-list.
Gael Alonso moved from Celta de Vigo’s second team to FC Andorra on a free in the summer. He has started and played in 19 matches in the league this season, consistently putting in impressive ball-progressing and defensive performances. I added Oleksandr Romanchuk to the data set thanks to @databhoys on Twitter’s excellent scouting report on Right Centre-Halfs.
Romanchuk joined Universitatea Craiova for €750k in the summer from Kryvbas in Ukraine. He has started and played in 15 matches in the Romanian Super Liga, along with 5 starts in the UEFA Conference League. The same as Alonso, Romanchuk has put in consistent, impressive ball-progressing and defensive performances this season.
Lastly, Eivind Helland has cemented his starting spot in the Brann backline with 28 starts in the league and 6 consecutive starts in the UEFA Europa League—including a quality performance in a 3-0 win against “The Rangers”. Helland is a solid ball progressor, but falls below the median line in defensive metrics. Being the youngest of the three, Helland has the highest potential to blossom into a star at Celtic, so for this, he is on my favoured list.
The same as I did in the Attackers’ scouting report, I am going to compare Alonso, Romanchuk, and Helland to current Celtic Centre-Backs (Liam Scales, Auston Trusty, and the returning Stephen Welsh!) So, let’s take a deeper look at the data of
Gael Alonso, 23, 1.82m, FC Andorra
Oleksandr Romanchuk, 26, 1.93m, Universitatea Craiova
Eivind Helland, 20, 1.96m, Brann
On-Ball
The scatter plot above compares the player’s “Overall Robust Z-score” (Y-Axis) to their “On-Ball Robust Z-Score” (X-Axis). On-Ball scores are weighted slightly higher than Defensive scores at a 55% weight.
To calculate the On-Ball Robust Z-Score, I weighted the Z-scores for the following metrics:
Pass Completion %: 20%
Progressive Passes: 35%
Progressive Carries: 25%
Acceleration w/ Ball: 5%
Long Pass %: 15%
In the scatter plot above, we see that Oleksandr Romanchuk ranks as the best On-Ball Centre-back amongst the peer group, scoring 0.06 better than the next best in Auston Trusty. Helland ranks 5th, with Alonso just behind in 6th, and Scales 7th. Welsh ranks 23rd out of 30.
Now, to compare the identified players to the current Celtic Centre-backs
Looking at the raw data sheet, we see that Trusty, Scales, and Welsh rank best in Pass Completion %, with Romanchuk and Alonso behind by ~5-7%. Contextualizing this, however, Alonso is the highest in Progressive Passes p90 with 13.28, meaning he is trying more ambitious passing, which causes his Pass Completion % to drop. Similar to Romanchuk, who is 3rd in Progressive Passes p90 with 11.3. Scales completes a high amount of passes, with a high 11.36 Progressive Passes p90. Helland is the most progressive carrier of the ball with 2.88 p90, with Romanchuk just below with 2.84. Trusty and Scales come next with 2.52 and 2.12 progressive carries p90. Alonso is 5th in progressive carries p90, which could be down to tactical instruction or it not being a strength of the player. We will need to look at the video to figure this out. Finally, Trusty is the highest in Long Pass % with 63.64 %, and Welsh is just trailing him at a 62.07% completion rate. Romanchuk and Helland complete long passes at a similar conversion rate. Alonso and Scales rank the lowest, both below 50%.
With a combined Progressive Passes and Progressive Carries p90 of 15.07, Alonso is the highest quantitative progressor of the ball out of the six players. With Romanchuk in second with 14.14, followed by Scales, Trusty, Helland, and Welsh. But, bringing into account completion percentages, Alonso drops to 4th. Romanchuk is the most accurate ball-progressor in the data sheet.
Defending
The scatter plot above compares the player’s “Overall Robust Z-Score” (Y-Axis) to their “Defensive Robust Z-Score” (X-Axis). Defensive scores are weighted slightly lower than On-Ball scores at a 45% weight.
To calculate this score, I weighted the Z-Scores for these metrics:
Aerial Duel Wins: 15%
Aerial Duel Win %: 20%
Defensive Actions: 15%
Defensive Duels Won%: 20%
Interceptions (pAdj): 20%
Tackles (pAdj): 10%
In the scatter plot above, we see that Gael Alonso ranks as the best defender in the peer group, with Rufai Mohammed behind by a difference of 0.06. Scales ranks fourth overall, followed by Romanchuk at ninth, Welsh at tenth, Trusty at fourteenth, and Helland last at 22nd overall.
Liam Scales wins the most Aerial Duels p90 with the 2nd highest win %. Though Trusty, winning 0.78 less than Scales p90, has the highest Win % at 67.09%. I would classify Alonso and Helland as equals in Aerial prowess— Alonso wins more by 0.13 at a -0.07 win%. Welsh is just behind Alonso and Helland with a win % of 61.73, with 3.41 Aerial duel wins p90. Romanchuk wins the fewest Aerial Duels at the lowest win % rate. Looking at Defensive Actions p90, Alonso is well above the rest and is the best in Defensive Duels Won %. Romanchuk also impresses here with the second-highest Defensive Actions p90 and the third-best Defensive Duels Won %. Alonso and Romanchuk also lead in Interceptions and Tackles pAdj, revealing them to be aggressive ball-playing defenders. On the other hand, Eivind Helland looks to be a more reactive defender with a second-best Defensive Duels Won % but the lowest in interceptions.
With a solid Aerial Duel Win %, a high defensive actions rate, the highest Defensive Duels Won rate, and the highest interceptions p90, Gael Alonso separates himself from the rest as a proactive, ball-playing defender. Oleksandr Romanchuk also impresses in the data, but his low Aerial Duel Win % at a low amount of Aerial Duel Wins p90 is a concern. Eivind Helland is good in the air, but less proactive in winning the ball than the rest of the set.
Data Analysis Conclusions
The Z-Score rankings and data analysis, both On-the-ball and defensively, highlight Gael Alonso and Oleksandr Romanchuk as two coherent right-sided partners for Liam Scales or Auston Trusty. And for the most part, they pass the analysis tests despite some concerns: Celtic Centre-Backs are required to be quality progressors of the ball at a high volume and, given the nature of the Scottish Premiership, must be good in the air and possess the ability to break up play high up the pitch. Alonso’s Pass Completion % and Romanchuk’s Aerial ability could be considered concerns— Romanchuk’s Aerial ability being a more glaring one. Eivind Helland looks to be a fit on the ball, but his below-average defensive scores fail to pass the analysis test. Helland is on the verge of a move to Bologna for €7 million, so I will remove him from the video analysis process. Unfortunately, I am unable to compile clips from full matches for Romanchuk in the UEFA Europa Conference League due to copyright infringement issues. Given that I cannot provide video, I find it futile to write a video analysis for him. I still see Romanchuk as a coherent transfer target for Celtic. Now, let’s take a look at video clips showing Alonso’s abilities on the pitch.
Video Analysis
As I do not have access to WyScout’s video clips, I am relying upon a Twitter compilation for Alonso.
It is not an ideal way to do video analysis, but I have gathered clips of Gael Alonso with the resources at hand to give a visualization of what the Data shows.
Gael Alonso
Video sourced from: @lg_castello97 Compilations of Alonso
The video below is a compilation of clips from @lg_castello97's videos on Twitter.
Alonso possesses an impressive passing-range, consistently completing passes from the back through the lines at short, medium, and long distances when he has to— even when under pressure. In the video, on several instances, Alonso deceives the opposition with his eyes or body positioning, opening up the angle for a more advantageous forward pass. Not only does he have the technical ability to ping passes at the proper pace and weight to teammates, but he also has the vision and, most importantly, the courage to play these more “difficult” vertical and diagonal passes.
He can also carry into both tight and large spaces to draw pressure from the opposition and complete a pass to the open man, with impressive patience and intelligent anticipation of opponents’ positions. Alonso is press-resistant with on-the-ball skill to evade pressures from opposition attackers. Another impressive aspect of his game is that when he receives a pass from a teammate, he is well-positioned to play the next pass forward.
In the video, Alonso’s FC Andorra are usually being pressed high up the pitch, which is becoming more of a common occurrence for Celtic. This proves two things: 1) Alonso is more than competent and comfortable in playing out of the back under pressure with effectiveness, and 2) this may explain his lower Progressive Carries p90, given that when pressed that high, it is better to play a forward pass than to carry the ball.
While there aren’t many clips included of his defensive abilities, a few show that he has a solid reading of the game—evidenced by his Interceptions per 90 rate. Alonso is a proactive defender by winning the ball high up the pitch. Given his top ranking defensively amongst the data set, his combined passing ability and defensive prowess make him look to be a very intriguing, impressive ball-playing Centre-Back.
From the video, my only concern with Alonso is that at times he plays balls almost too difficult for teammates to control, usually being hit too hard toward their feet. Is this a weakness of Alonso or his teammates? For me, the burden falls more on his teammates, but a player also has to know if their teammates’ first touch is poor, maybe don’t zing one into him? It is a very small concern and nitpicky, as I had to find something from the video to mark as a “concern”.
Final Conclusions
Gael Alonso
Above is Gael Alonso’s heatmap from the 2025-26’ season. He is frequently active in build-up and progression play from his own goal into the midfield with 66 completed passes per 90. Sifting through the data and video, Alonso is a profile that Celtic are in desperate need of: a right-sided ball-playing centre-back who is skilled in inventive passing, duel-winning, intercepting, and is competent in Aerial duels. Playing in the highest-possession side in La Liga 2 (58.6%), Alonso is familiar with the role that would be required of him at Celtic. FC Andorra have never sold a player for more than €2m according to Transfermarkt, and while he has only been there for half a season, I think that he would be in the coveted >£3m range if Celtic were to attempt to sign him.
This concludes my January Scouting Reports series— unless we are still in for a Defensive Midfielder given the now dead-in-the-water Niko Sigur links. In the coming days and weeks, if Celtic are to actually sign some players, I will put out analysis of the player and their fit within Celtic, either here or on Twitter. If you are interested in my work and want to know when it is posted, please subscribe here or follow me on Twitter @heathtimpe.