Objective To quantify the influence of soccer-specific fatigue on functional stability. Participants and design Ten male semi-professional soccer players completed a 90 min treadmill protocol replicating the activity profile of match-play with a passive 15 min half-time interval. Main outcome measures At 15 min intervals players completed a 30 s single-legged balance task on an unstable platform. Balance performance was quantified as a stability index and the mean deflection of the platform. Results There was no significant (P>0.05) main effect for exercise duration in the stability index, suggesting that balance performance was maintained throughout the simulated match. However, the mean deflection of the platform was significantly (P<0.05) shifted toward anterior displacement during the last 15 min of each half. Conclusion A change in balance strategy was evident during the latter stages of match-play, which may increase injury risk. It is recommended that soccer players perform proprioception training in the rested and exercised state to further develop neuromuscular control.