National football coach Radojko Avramovic is in hospital after falling ill at a football event on Saturday.
In a statement, the Football Association of Singapore (FAS) said the 62-year-old Serb is receiving medical attention at Changi General Hospital.
FAS president Zainudin Nordin said national players as well as members of the Association's management and medical committee have been informed. He added the coach is currently in a stable condition.
Avramonic has been in-charge of the national team since 2003 and led the Lions to two Asean Football Championships in 2004 and 2007.
He recently faced calls from fans to step down after the team lost all six games in the third round of the 2014 FIFA World Cup qualifiers.