The FA Cup is set to feature a new rule allowing clubs to make a fourth substitution in extra-time from the quarter-finals onwards.

Teams who have used three replacements during the sixth round, semi-finals and final will then be allowed to introduce another player, should the game be level after normal time.

The new format was first trialed earlier this summer in the Copa America tournament.

"With The Cup now adopting a straight knockout format from the quarter finals onwards, the introduction of a fourth substitute in extra time will bring extra intrigue and interest," says FA chief executive Martin Glenn.

"Also, from a technical point of view, it will be interesting to see how managers use the chance to make an additional substitution in such high-profile games and the impact it has on the final result.

"Player welfare and being mindful of the number of games people play at the elite level has also been a consideration."

Two of the last three finals have gone to extra-time.