Patrick Ekeng, a 26-year-old defensive midfielder, died on Friday after collapsing during action for his Romanian Dinamo Bucharest club.
Ekeng, who joined the club in January, fell to the ground exactly seven minutes after coming on as a substitute in the league game against Viitorul Constanta.
He was rushed to hospital where he died after over one hour of battling to restore his life.
“Resuscitation attempts were made for an hour and half without success,” Liviu Paltinean, the team doctor, told journalists.
“I can’t believe it. It’s a nightmare. For me, for the team and for all Dinamo supporters. It’s too much,” said club executive director and former player Ionel Danciulescu.
Ekeng’s former club Cordoba tweeted: “We have no words to express our sadness at the loss of Patrick Ekeng. We mourn your loss.”
Ekeng had also previously played for Le Mans and Lausanne.
His death is a reminder of Marc-Vivien Foe, also a Cameroonian midfielder, who died after collapsing during a Confederations Cup match against Colombia.
He represented his national team at the 2015 Africa Cup of Nations.