How old are Europe's squads, really?

Calendar age vs effective age across Europe's big five, 2025-26.

Calendar age is how old a club's players are, weighted by the minutes they've played this season. Effective age replaces birthdays with career top-flight minutes, read against a position-specific trajectory of heavily-used players (the 75th percentile at each age). A 25-year-old winger with 18 000 career minutes matches the mileage of a 28-year-old winger on that trajectory; their effective age is 28.

The two charts below plot every club in Europe's top five leagues on the same y-axis. The first reads calendar age, the second reads effective age. Where a league's cloud sits answers who's older. How tall the cloud is answers how much clubs in that league differ from each other. The gap between a club's left-chart and right-chart position reveals which squads carry more career minutes than their birthdays imply, and which carry fewer.

Weighted squad age, top-5 leagues · 2025-26

One dot per club. Bottom numbers show each league's weighted average.

Roster

Δ per club (effective minus calendar age)

Dots above zero carry more career minutes than their birthdays imply; dots below carry fewer.

What jumps out

A note on "old"

Effective age measures career mileage at a position-typical trajectory. It is not biological age and it is not a decline indicator. A 28-year-old with an effective age of 32 has the minutes profile of a more weathered player, but whether they're about to slow down is a different question this metric can't answer.

What it does usefully signal. Career minutes track transfer-value depreciation and wage-curve decay from the late-20s peak. A squad heavy with high-mileage players has absorbed more professional workload than its birthdays suggest, and the commercial side of football reads that pattern directly.

What we expected to find but didn't. The obvious hypothesis is that worn players should break more often. We checked it against Transfermarkt's per-matchday availability data for 1,807 outfielders across the top 5 leagues in 2025-26. Players in the top tercile of Δ (the "worn" group) have a 5.0% muscle-injury rate; those in the bottom tercile ("fresh") have 7.0%. Lifetime mileage does not predict seasonal muscle injuries at player level. In-season workload and individual medical history swamp the career-mileage signal, which is consistent with the sports-science literature measuring current-window distance and sprint volumes rather than career totals.

A caveat on the proxy. The sports-science literature on player aging uses distance covered and sprint volumes, not cumulative minutes. Sprint and high-intensity running decline sooner and more sharply than total distance, and total distance declines sooner than raw minutes on the pitch (Rampinini et al., 2022; Barça Innovation Hub). Wide players and forwards show the steepest physical decline, and those are the same positions that move most under our position-correction (median shifts of +0.7y for strikers and +0.3y for wingers relative to the overall curve). Total top-flight minutes is a blunter tool than the research standard, but it's the mileage signal openly available across all big-five leagues.

The per-position split here is inspired by Michael Caley's Building Marcel Part II work at Expecting Goals, which fits GAM aging curves per skill (shooting, passing, defending) on performance data. Our object is different (minutes accumulated, not skill output), but his finding that wingers peak earlier than centre-backs motivates grouping our curves by position. Read his piece for the sharper version of the question.

Method

Rosters, dates of birth and 2025-26 domestic-league minutes come from the dcaribou Transfermarkt dataset. Career minutes are collected from Transfermarkt and aggregated across top-flight and second-tier leagues, continental competitions and domestic cups. Player effective ages are inversions of a cubic career-minutes-vs-age curve fit at the 75th percentile on current top-5-league actives, fit separately per position bucket (GK/CB/FB/CM/AM/WM/ST). GK and AM fall back to the overall curve because their fit samples are too thin.

Club aggregates weight each player by their 2025-26 domestic-league minutes; a player with zero minutes doesn't drag the mean.