Soccer:Japan's top players were in shock today after former international team mate Naoki Matsuda was rushed into intensive care after he collapsed during training.

Medical personnel rushed to the 2002 World Cup player's aid yesterday after he collapsed with suspected heatstroke. His JFL team Matsumoto Yamaga later said he had gone into cardio-respiratory arrest.

Doctors put 34-year-old Matsuda on an artificial respirator and described his conditions as "extremely critical."

"He was stable this morning but there was no change in his condition," Yamaga manager Yoshiyuki Kato said today:

Doctors suspect the player may have suffered a heart attack after he arrived at hospital unconscious and not having responded to heart massage, his club said.

Record temperatures across Japan have caused a rise in heatstroke cases with 43 deaths reported in the two months through the end of July.