Uefa has changed its rules regarding players being able to represent two different clubs in the same European Cup competition commencing next season.
As it stands, January signings cannot play for a second club in the Champions League or Europa League if they have already featured in that competition. Moving forward, a club may register three new eligible players without any restrictions after the group stage.
Other key changes will allow a fourth substitute in extra time of knockout ties, while 12 substitutes can be named in the finals.
A fourth substitute may be introduced in knockout matches – but only during extra time. This will not affect the other three substitutions.
Teams contesting the Champions League and Europa League finals, plus the Uefa Super Cup, will now be able to name a matchday squad of 23 players instead of the 18 allowed in the rest of the competition.
Uefa believe this will provide clubs and their coaches an opportunity to be more flexible with substitutes and facilitate squad management for the most important fixture of the season.
Currently, all Champions League games kick off at 19:45 BST/GMT, although Uefa can make exceptions to this rule. Staggered kick-off times will be introduced as standard next season.
In the group stage, two matches will be played on the Tuesday, and two on the Wednesday, kicking off at 17:55 BST/GMT. This could provide clubs in the UK with logistical headaches for their midweek games.
All fixtures on the last matchday will be played simultaneously.
The rest of the matches, including all the knockout ties, will kick off at 20:00 BST/GMT.
Europa League matches from the group stage until the last 16 will kick off at 17:55 and 20:00. The quarter-finals, semi-finals and final will all kick off at 20:00.