Before a footballer can join a new club, they must undergo a comprehensive medical examination. This process assesses the player's overall health and fitness, identifying potential underlying issues. While not legally required, these exams are essential for clubs to evaluate risks before completing a transfer. The tests can take up to six hours, encompassing various assessments.

The medical typically involves physical exams, cardiovascular health evaluations, and laboratory tests. Doctors measure height, weight, blood pressure, and heart rate. Cardiovascular tests include electrocardiograms and stress tests to assess heart health. Blood, urine, and drug tests are also standard. Neurological tests evaluate psychological factors, balance, coordination, and concussion assessments.

Results are analyzed by the buying club's medical staff. Players don't technically "pass" or "fail"; the club assesses risks based on findings. A team may still sign a player despite issues. Examples like Ruud van Nistelrooy's delayed Manchester United transfer and George Boyd's failed move to Nottingham Forest showcase the impact of medical results.

During the transfer window, medical facilities are prepared for increased demand. The Manchester Institute of Health and Performance (MIHP) emphasizes flexibility and round-the-clock availability for clubs. They prioritize high clinical standards and comprehensive evaluations, providing verbal reports the same day. The process can be stressful for players, with some more apprehensive than others.