The change is to better reflect the average age of participants in PL2, which is currently 19 years old.
Leeds had one of the youngest squads during last year's PL2 Division 1 campaign, with several Under-18 players featuring due to injuries at first-team level and a thin Under-23 squad.
This did provide opportunities to 16-year-old Archie Gray who remains among the highly-rated youngsters currently at Leeds' academy.
The Premier League's old system - which has been in place since 2016 - permitted clubs to name three over-age players in their squads, meaning those aged 23-and-above such as Chelsea's Lewis Baker, could feature in development stage football.
New rules dictate teams can field five over-age players, however 22 and 23 year-olds will now count towards that quota as the league transitions back to an Under-21 format.
"The amendment to the age limit, which was previously under-23, has been introduced as part of an ongoing review of the Elite Player Performance Plan (EPPP) to better align with the EFL Trophy and international competitions."
"Clubs will, however, be permitted to use five (previously three) over-age outfield players and one over-age goalkeeper, in order to transition from its under-23 format."
"The aim is to continue providing opportunities for the best young players to play alongside and against older and more experienced players. Premier League 2 is part of a suite of competitions that aims to best prepare players to make the transition to senior football," an official statement read.
Leeds were crowned PL2 Division 2 winners in 2021, earning promotion to the top flight of Under-23 football in England boasting a team featuring the likes of Joe Gelhardt, Sam Greenwood, Charlie Cresswell and Crysencio Summerville.
The Whites were relegated from Division 1 last term along with Derby County's youngsters.
They will once again compete in the second tier during 2022/23.