Young Lions

By entering the Young Lions into the S.League, the FAS hopes to expose young players to top-level competition, thus helping to prepare them for international tournaments such as the Southeast Asian Games. While the bulk of the Young Lions squad is made up of members of Singapore's national under-23 team, the club also takes in promising young foreign players (e.g. Luka Savić). However, foreign players are normally only recruited into the Young Lions squad if they could potentially change their nationality to Singaporean and be eligible to play international football for Singapore at some point in the future.

Malaysian domestic competition

In 2011, the Football Association of Singapore and the Football Association of Malaysia reached an agreement that would see greater cooperation between the two nations. One of the intended avenues would see Young Lions play in the Malaysian Super League and Malaysia Cup from 2012. The squad will be permitted up to five local players over the age of 14–16 players, as well as a number of overseas players in accordance with the quota set out by the rules of the Malaysian competitions. Ultimately, a new team was created, the LionsXII, while the Young Lions remained in the S.League.

National Football Academy

Most of the Young Lions players come from the NFA (National Football Academy) and new players (from the NFA) will be promoted to the Young Lions squad every season.

The National Football Academy enters both the Singapore NFA U-17 and Singapore NFA U-18 teams into the Prime League to allow their players to gain more exposure and match experience by playing against older and more established players.

Foreign players

In 2023, Young Lions signed the Japanese duo Jun Kobayashi and Kan Kobayashi from Albirex Niigata (S) becoming the first foreign players since France's Benjamin Bertrand from Tours in 2016. In preparation for the 2024–25 Singapore Premier League season, Young Lions signed two additional Japanese players, Kaisei Ogawa and Itsuki Enomoto, and the Australian Rashid Hayek from Western United, making it the first time the club had five foreigners in the squad. On 28 March 2025, Young Lions recorded their highest ever win during the 2024–25 Singapore Cup fixtures against Albirex Niigata (S) where Kaisei Ogawa became the second players in the club history to score four goals in one match since Zikos Chua against Tanjong Pagar United on 7 August 2022.

After a reshuffle in the Football Association of Singapore seeing Forrest Li as the FAS new president in 2025, Young Lions saw a major overhaul in the club during the 2025–26 season where they signed a new partnership with Denmark manufacturing company Select, ending a deal with Nike after 17 years. The club also got a main sponsor for the front of their jersey with Chinese state-owned automobile company, Dongfeng. Young Lions also went on to sign a few youngsters from Brazil, including Abner Vinicius, Joilson, Lucas Agueiro and Sérgio Mendonça while they loaned a few under-21 foreign players from Lion City Sailors, such as Enrico Walmrath, Harry Spence and Benjamin Žerak. Needing an experience local players in the squad, Young Lions than recruited Izwan Mahbud and Abdil Qaiyyim Mutalib to strengthen the team.

In the 2026–27 season, Young Lions focus their attention on recruiting Japanese players where they would sign Shuya Yamashita, Miyu Sato, Daisuke Sakai, Toi Kagami and Hisatoshi Nishido. The club also signed EFL League Two player Kai Whitmore, who previously played for Newport County. Young Lions than recruited experience local player, Hafiz Nor to strengthen the team midfield.