Footy fans can normally get excited when a star has one with their club – it usually means they are within hours of finalising a deal with the team.
But they don’t always go exactly to plan.
A number of huge deals have been scuppered over the years due to failed fitness tests.
Big name players like Ruud van Nistelrooy, Victor Valdes and Gabriel Milito have all failed medicals at some point in their careers.
Click through the gallery above to see 17 players who failed medicals.