Injury news is a traded commodity before it is a headline

Team sheets and fitness updates move betting prices, which makes medical information a security that leaks like one.

An hour before a match somebody knows who is playing and the market does not. That gap is worth money, and every league that has thought seriously about integrity has had to confront the fact that its medical room is, functionally, a source of inside information.

The mechanics are simple. Betting markets price a fixture on expected line-ups. Remove a key player and the price moves immediately and predictably. Anyone with reliable advance knowledge of an unavailability has an edge that requires no skill at all, and the number of people who legitimately hold that knowledge is large: medical staff, coaches, analysts, kit staff, the player, his family, his agent.

Leagues have responded with disclosure rules, which is the correct instinct. Publish an injury report on a fixed schedule and the information becomes public simultaneously, killing the edge. American leagues have run mandatory reports for years, partly for exactly this reason, and enforce them with fines that are occasionally substantial.

European football mostly has not, preferring a culture of tactical secrecy in which managers actively mislead about fitness because it is thought to be a competitive advantage. I think that trade is badly priced. The advantage of concealing a fitness doubt for twenty-four hours is small and often illusory, since opponents scout the same information anyway. The cost is an unregulated information asymmetry sitting next to a wagering market worth more than the league's broadcast deal.

There is a medical privacy problem in the middle of this, and it is genuine. A mandatory public report on a specific diagnosis is health data being published because of a betting market, which is an uncomfortable thing to say aloud. The workable compromise is status without diagnosis: available, doubtful, out, with no clinical detail. That satisfies the market and leaves the medical file alone.

Clubs will resist because they like the secrecy, and betting partners will not push hard because volatility suits them fine.

Until the reporting is mandatory and simultaneous, the honest description of a Friday fitness update is not journalism. It is a leak into a market, and everyone involved knows the price.