They were conceived as a developmental team, aimed at giving young Singaporean players a platform to learn their craft and hone their skills as they worked for a spot in the national side.
The make-up of the LionsXII has changed every year since its 2012 debut in Malaysian domestic football competitions, but the players have always remained local, with the age of the squad the only point of contention.
But next year, the team could see foreign players on their roster.
Football Association of Malaysia (FAM) deputy president Afandi Hamzah told The New Paper yesterday that even as they deliberate with their Singapore counterparts over an extension for the LionsXII to play in their club competitions, the Football Association of Singapore (FAS) has requested permission to include four foreign players in the squad.
A Memorandum of Understanding signed in 2011 saw the LionsXII enter Malaysian competitions in 2012, while a Malaysian side - the Harimau Muda - join the S.League.
That agreement expires at the end of this season.
"I was informed that Singapore has requested to have four foreign players in the team next year, and we will discuss this further," said Afandi.
"If we find that it is okay, it won't be a problem. But we have not made any confirmation yet, on this or the MOU.
"The MOU expires this year, and whether we extend or not is, of course, subject to discussion."
Current rules allow each club to sign four foreign players - one of whom has to be an Asian import - in Malaysia's club competitions.
In its first year, the LionsXII were an Under-28 side, with 15 players over the age of 23, and V Sundramoorthy's men finished second in the Malaysian Super League (MSL).
The following season, they became an Under-23 side with five over-aged players, as Sundram led his charges to the MSL title.
Age issues have played less of a role in the squads since then, with Fandi Ahmad, coach since last season, including only three players aged 23 and below in his 18-man matchday squad against Sarawak last night.
In response to TNP queries, an FAS spokesman said only that the matter is being discussed, with "several options" being explored.
In the lead up to the 2012 season, the LionsXII did have the option of signing up to three foreign players, along with the 13 other clubs in Malaysia's top division then, but declined.
While FAS president Zainudin Nordin said at the time that the LionsXII was "a platform for our young players on a big stage", the change in position could have something to do with the proposed Asean Super League, an elite club competition that could be launched next year, or in 2017.
Former ATM FA head coach B Sathianathan thinks fielding foreign players in the LionsXII is not a bad idea.
"This brings it back to the good old days when Alistair Edwards and Abbas Saad played for you guys, and I think it could be good for the league," he said.
"I'm looking at it from a football viewpoint, and I think this could make the MSL more exciting, and for me, this kind of competition is always a good thing."