Bahrain and Hong Kong have been confirmed as Singapore's opponents, in addition to neighbours Malaysia, for three friendlies in September and October.
The Lions will face Bahrain in Manama on Sep. 1 as part of their AFF Suzuki Cup preparations.
On Oct. 7, they will host Malaysia at the National Stadium before travelling to Mong Kong Stadium for an Oct. 11 clash with Hong Kong, who held China in two draws in AFC World Cup qualifying last year.
"Bahrain and Hong Kong are good opponents," Singapore coach V. Sundramoorthy said. "I have said before that it is important for us to have high-quality matches against strong opponents, so we are happy to have these matches lined up, together with the Causeway Challenge against Malaysia."
Sundram has selected a 24-man squad for the match against Bahrain, with Hougang United forward Iqbal Hussain selected as one of three players from his S.League side, after veteran Fazrul Nawaz was ruled out for at least five months with an ACL tear in his left knee.
Iqbal, who has scored four S.League goals this season, said: "I am excited to be called up by coach Sundram for the match against Bahrain. It shows that my hard work in the S.League has paid off, and I am looking forward to learning not just from him but also from the seniors in the team."
With the Suzuki Cup less than three months away, Sundram added that the matches would provide the perfect preparation.
"Hong Kong has good and physically strong players, some of whom are naturalised. Their playing style is similar to some of our opponents at the AFF Suzuki Cup, and we are looking forward to the game. Bahrain, being 33 places above us in the FIFA world ranking, will also be a good test for us."
A big crowd is expected for the Causeway Challenge against Malaysia. Tickets go on sale from Sep. 1, with concession entry at an early bird price of S$6.