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.

Khawaja defies the obituaries with half-century in third Ashes Test
FIFA launches $60 ticket tier amid criticism of 2026 World Cup pricing
Abu Dhabi Knight Riders snap Desert Vipers streak in one-run thriller
Dembele named FIFA player of 2025, Bonmati wins women's award
Australia's Green becomes IPL's most expensive overseas player
