Former Japan international Naoki Matsuda died on Thursday after collapsing at training earlier in the week.
Matsuda, 34, suffered a heart attack during a 15-minute warm-up run before training with his club Matsumoto Yamaga on Tuesday. He was taken to hospital unconscious and slipped into a coma. He was placed on life support but did not regain conciousness.
"He passed away today at 1:06 p.m.," Yamaga president Hiroshi Otsuki said. "Since Tuesday there has been an outpouring of support from Matsuda fans all over Japan."
The ex-Yokohama Marinos defender played 40 times for Japan, including at the 2002 World Cup.
One time Japan team-mate Shunsuke Nakamura said after he had visited the hospital to pay his respects: "He was dynamic in every aspect and he was a kind of big brother for everyone in a positive sense. A smile was on his face, making me wonder if he really could not move."
Ex-Japan captain Tsuneyasu Miyamoto said: "It's a huge shock. I will always remember playing along side him at the 2002 World Cup. He was a great team-mate."
Philippe Troussier, Japan's coach at the 2002 World Cup, told Fuji TV: "Matsuda was a kind of loyal soldier. He listened attentively to what I said. He was polite and always a reliable key man in the team."
FIFA president Sepp Blatter said: "On behalf of FIFA and the worldwide family of football, I wish to extend our condolences to you, to the Japanese football community and, most importantly, to Naoki Matsuda's friends and loved ones. Please let them know that today the football community stands by their side."