The International Football Association Board (IFAB) has postponed the introduction of a new blue card as part of trials of sin bins in professional football, sources have told ESPN.

Football's lawmakers announced in November measures to improve player behaviour and increase respect for match officials, which included temporary dismissals for dissent and specific tactical offences.

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The IFAB was due to announce protocols for the trial on Friday, including a blue card to distinguish the offence from a yellow and red card.

However, there will now be no announcement until after the IFAB Annual General Meeting (AGM) on March 2, when all proposed trials and law changes are discussed before being approved for use from June 1.

FIFA had distanced itself from the reports of a blue card late on Thursday.

"FIFA wishes to clarify that reports of the so-called 'blue card' at elite levels of football are incorrect and premature," the sport's governing body said in a statement on Thursday.

"Any such trials, if implemented, should be limited to testing in a responsible manner at lower levels, a position that FIFA intends to reiterate when this agenda item is discussed at the IFAB AGM on 1 March."

Sin bins have already had a successful implementation in the lower levels of football since 2019-20, with players ordered to leave the field for 10 minutes if they show disrespect to an official.

The new trial for higher-level football, which is expected to last at least 12 months, will include situations in which a player deliberately takes out an opponent in an attacking situation when a red card isn't warranted.

One such example was Italy defender Giorgio Chiellini dragging back England's Bukayo Saka by the scruff of his neck in the final of Euro 2020.

Grassroots football in England, which has a particular problem with referee abuse from players, has been using the yellow card to indicate the offence across 31 leagues since the 2019-20 season.

Even after the trial is formally approved at the AGM next month, fans won't be seeing the blue card in top level competitions like the Premier League, LaLiga, the UEFA Champions League, Euro 2024 or the Copa America, however.

The trial over the course of next season won't be permitted at the very top level, and it would be 2026-27 at the earliest before it could enter the Laws of the Game.

Indeed, there have been various trials in lower leagues in past years with the aim of combating dissent, such as moving a free kick forward 10 yards, which have not made it into the Laws.

Sources have told ESPN that there is limited support for sin bins among the top leagues, and while the Football Association has the option to test it in competitions such as the Women's Super League and the FA Cup, it isn't expected to be taken up.