Arne Espeel, a Belgian goalkeeper, died during the second half of his game on Saturday at age 25.
Espeel, who played for Winkel Sport B in the second provincial division of West Brabant in Belgium, saved a penalty kick but collapsed to the ground afterward, according to Belgian media.
Despite medical staff treating him with a defibrillator, he was pronounced dead at a local hospital.
"Winkel Sport is in very deep mourning by the sudden death of Arne Espeel," the club said in a statement. "We wish family and friends of Arne our heartfelt condolences in this heavy loss. Football is an afterthought."
"This is a disaster and a shock to everyone," team manager Patrick Rotsaert added, via The Independent. "Arne had been with the club all his life and was very loved. He was a wonderfully sympathetic boy, always in a good mood and willing to help. This is really a heavy blow. First of all for his family and also our entire club."
Espeel's family and teammates were among 1,000 mourners on Monday during a walk of silence in Sint-Eloois-Winkel.
An autopsy was scheduled for Monday, but results have not been released, according to Reuters.
The Associated Press contributed to this report. Read more of this story from FOX News.