UEFA introduced an amendment to its regulations for the Champions League, allowing clubs greater flexibility in managing their squads during the league phase of the competition.
The governing body confirmed on Thursday that clubs will now be permitted to temporarily replace one outfield player suffering from a long-term injury or illness up until matchday six.
The measure, approved by the UEFA Executive Committee, is designed to prevent squads from being unfairly reduced and to protect players from excessive workload.
The UEFA Champions League will kick off next week.
The first week of the league will witness many interesting fixtures as Chelsea will head to face Bayern Munich, Premier League champions Liverpool will host Atletico Madrid, and Newcastle will host La Liga champions Barcelona at St James' Park.