Current Millwall and Montenegro goalkeeper Matija Sarkic died on Saturday at the age of 26, the Championship club confirmed.
Sarkic fell ill in his home country while on international duty. Montenegrin daily newspaper Vijesti reported Sarkic died in an apartment in Budva early in the morning.
"Everyone at the club sends their love and condolences to Matija's family and friends at this immensely sad time," the Championship club said in a statement.
"The club will make no further comment at this time and asks that the privacy of Matija's family is respected."
Sarkic made nine saves in Montenegro's 2-0 defeat to Belgium in a friendly last Wednesday and was named man of the match for his outstanding performance.
Born in Grimsby, England, Sarkic played for Aston Villa and Belgian side Anderlecht at youth level. He made 33 appearances for Millwall since joining in August 2023 from Premier League side Wolverhampton Wanderers.
Australia were dealt an early blow in their quest to reach the Super Eight stage of the Twenty20 World Cup after the depleted former champions crashed to a 23-run defeat by Zimbabwe in Colombo on Friday.
Arsenal has wasted the chance to restore their six-point lead at the top of the Premier League table as they were held to a 1-1 draw at Brentford on Thursday, with Noni Madueke's second-half header cancelled out by Keane Lewis-Potter.
Defending champions India continued their march towards the Super Eight stage of the Twenty20 World Cup with a 93-run win over Namibia in a group A contest at Arun Jaitley Stadium on Thursday.
Brothers Justin and Anthony Mosca guided Twenty20 World Cup debutants Italy to their first win in the tournament, as their unbeaten half-centuries secured a dominant 10-wicket victory over Nepal in a Group C clash on Thursday.