Champions League rule changes: Everything you need to know for 2026-27 league phase

The main draw of the 2026-27 Champions League will get underway this week, with 36 teams set to compete across eight matchdays in the league phase.

Paris Saint-Germain will be looking to win the competition for a third straight season after beating Arsenal on penalties to win their second Champions League trophy in May.

Luis Enrique's side will face competition from several European heavyweights, including Arsenal, Manchester City, Liverpool, Barcelona, Real Madrid and Bayern Munich.

First, the heavy hitters will need to negotiate the league phase where the top eight will advance straight to the last 16, while the teams from ninth to 24th spot will enter a playoff round.

There may be no changes to the qualification format for the third edition of the Champions League league phase, but there are a few new rules to look out for in the latest instalment of UEFA's premier club competition.

Here, Sports Mole covers everything you need to know about the new rule changes for the 2026-27 Champions League.

Referees to be hot on delay tactics

The Champions League will be looking to reduce time delays with rules that have already been introduced across the top European leagues this season.

Players being substituted will need to leave the field of play within 10 seconds; otherwise, the incoming player will have to wait until the first stoppage after a one-minute wait.

Meanwhile, the referee has the right to provide a five-second countdown for players to restart play from throw-ins and goal kicks.

The throw-in will be reversed if a team falls foul of a countdown, while a corner will be awarded to the opposition if the goalkeeper fails to take a goal kick in the allotted time.

In regard to players requiring medical treatment, they will need to leave the pitch for a minute before they can return to the action, although the rule does not apply to goalkeepers.

There are several other exceptions to the rule, including when a player is on the receiving end of a foul that leads to a yellow or red for the opposing player.

UEFA to increase VAR remit

UEFA have announced that VAR will be used in new areas for the 2026-27 season, including in cases of mistaken identity.

VAR officials can take action when a referee has sanctioned the wrong players, although the offence in question cannot be reviewed.

Those in the VAR booth will also be able to intervene when a second yellow card has been incorrectly awarded, allowing them to send the referee to review the action in question on the pitchside monitor.

The final two areas where VAR will have a say are related to fouls from an attacking team before a corner or free-kick, and clarification around potential handball offences from goal kicks.

Will Champions League referees punish players for covering their mouths?

The issue of players covering their mouths became a real issue when Benfica's Gianluca Prestianni pulled his shirt over his mouth when speaking to Real Madrid's Vinicius Junior in February's Champions League clash.

Prestianni was accused of racist abuse before he was later found guilty of homophobic conduct following a UEFA investigation, leading to a six-game ban with three of those matches suspended.

The incident led to FIFA implementing a rule for the 2026 World Cup where players could be sent off if they covered their mouth while in confrontation with an opposing player.

Miguel Almiron became the first player to be sent off for the offence in Paraguay's group game against Turkey before Piero Hincapie was later dismissed for falling foul of the same rule in Ecuador's last-16 defeat to Mexico.

UEFA have confirmed they will not be following FIFA's approach, but referees can brandish a yellow card if a player covers his mouth in a way that is deemed to be unsporting behaviour.

Like Prestianni, players can still be retrospectively punished if an investigation is required after the game in question.

FIFA were also keen for VAR to intervene when corners were incorrectly awarded during the World Cup.

In a slight contrast to FIFA's application of VAR, UEFA has explained that a corner will only be overturned when it is a very clear case and the decision can be made without delaying the game.

UEFA implement new booking rules

UEFA have made changes to the number of accumulated yellow cards that can lead to a suspension in the main draw.

Previously, players would pick up a one-match suspension for three accumulated yellow cards and further bans after five and seven cautions.

This season, players will receive extra leeway, with the threshold now at four yellow cards and then further suspension after six, eight and 10.

Yellow cards will expire upon the completion of the quarter-finals, meaning a player will only be suspended for the final if they receive a red card in the second leg of the semi-finals.