Article by James Dailey
I started a deep dive into analyzing Scott Brown’s age-based performance decline this past summer, which was catalyzed by an exchange with Alan in the comments section of Celticbynumbers prior to the first Cluj qualifier. My “eye test” was telling me that Brown was looking well off the pace and was worrying that Lennon was “building the team” around a 34-year-old midfielder who could be hitting the wall. Subsequently, Lennon stated in public that Brown had been carrying and playing through a toe injury, and his form definitely picked up heading into September. However, my digging and research continued.
Part of my analysis was to aggregate and calculate SPFL league averages for all midfielders, and defensive midfielders specifically, and then compare Brown’s performance statistics. I also created a comparable “benchmark” using peer group central midfielders for Europa League clubs. This analysis resulted in a lot of observations, but I’ll highlight a few big ones:
Brown’s offensive production is in line with the average of non-Celtic and Rangers midfielders. Basically, I calculated an average excluding Stephen Davis, as his passing stats are so positive that they skew the overall sample. Relative to his Europa League peer group, Brown is way below average offensively.
Brown’s defensive production remains very good compared to his SPFL peers, but as Alan has chronicled, he has been in steady decline. That decline has taken him from what had been an elite defender without peer in the SPLF to being very good and now within a pack of other SPFL players. Compared to his Europa League peer group, Brown’s decline has taken him from the elite top to the middle of the pack – i.e. about average.
Holy crap does this guy Liam Donnelly’s defensive data stand out as if he some kind of roving midfield monster!
The two defensive metrics where Brown still stands out as excellent are interceptions and recoveries. But let’s take a look and compare Brown and Donnelly’s defensive stats this season so far:

Brown’s overall passing stats are better than Donnelly’s, Donnelly turns the ball over a little more than Brown, and neither do much creatively with their passing. But defensively and general movement around the pitch? It really is not a contest at this point, and Donnelly’s stats are vastly superior to anyone else in the SPFL. Donnelly is also 23 years old, 2 inches taller and about 20 lbs. heavier than Brown.
If Brown’s supposed role is to protect the back four as a sort of modern day stopper, then the stats show that Donnelly is doing that role significantly better. And before anyone is tempted to make arguments about the difference in teams, possession, tactics, I’ve calculated all the stats adjusting for possession, Passes Per Defensive Action (PPDA), etc., and Donnelly’s lead over Brown is even larger in most metrics.
I think against a lot of the SPFL there is a legitimate debate about whether this stopper role is even needed, and Ismaila Soro’s stats suggest he will bring a vastly upgraded creative skillset vs what Brown offers.
However, if a stopper is to be used, then Celtic could do a lot worse than Liam Donnelly. In fact, we already are.