This study investigated the renal function of soccer players after an entire game-season. Thirty-five athletes recruited to play for the Macae Futebol Clube were invited for this study, of which 18 athletes completed the entire game season. Blood and 24-hour urine were collected at the beginning (Pre-Season) and the end of the game season (Post-Season). Kidney functions were assessed by calculating the urinary excretion, clearance, and fractional excretion of the selected solutes. Plasma creatinine, sodium, total protein, and osmolality were lower in the Post-Season . In contrast, plasma urea was higher in the Post-Season period. Urinary excretion of urea was reduced while albumin excretion was higher in comparison to Pre-Season. The clearances of creatinine, total proteins, and albumin were higher in the Post-Season period. In accordance, the fractional excretion of albumin increased. On the other hand, the clearance and fractional excretion of urea was lower in the Post-Season period. These results show that soccer-associated exercise throughout the entire game-season induces kidney functions adaptations that may prevent dehydration in these athletes through increased urea reabsorption to conserve water. In addition, this data corroborates to increased glomerular permeability to plasma proteins, such as albumin, that soccer players may experience.