Europe's top clubs, including some Premier League sides, have held discussions about using six substitutes per game to ease the workload on players.
Sides met at the European Football Clubs' (EFC) general assembly in Rome last week to discuss issues within the game.
It was not officially on the agenda or pushed by the EFC, but clubs had informal, private discussions about utilising 28-man squads - up from the current 25 - and six substitutes.
Manchester City, Liverpool, Manchester United, Arsenal and Nottingham Forest were among those from the Premier League in Italy.