Ivan Turina, the goalkeeper for Swedish club AIK, has died at the age of 32.
The Croatian is believed to have died in his sleep on Wednesday night, under no suspicious circumstances.
A club statement said: "AIK Football thoughts go out to Ivan's partner and two daughters and his other relatives and friends.
"AIK Football has informed the team and other employees about what happened.
Turina made his Croatia debut in a friendly against Hong Kong seven years ago
"We ask all to respect all parties and allow them to mourn in peace."
Turina, who won one cap for Croatia in 2006, had agreed a new contract with the club until 2016 during AIK's pre-season trip to the Unites States in February.
He joined AIK from Dinamo Zagreb in 2010 and went on to make 89 appearances for the Stockholm side.
The 'keeper also previously had spells with Greek side Skoda Xanthi and Lech Poznań.