Fourth sub to be introduced in German Cup

A statement issued by the DFB (German football association) on Friday said the change would apply to both the men's and the women's cup competitions for the rest of the 2017-18 season. 

This came after the sport's international rule-making body, the International Football Association Board (IFAB) approved the DFB's application to take part in the project, aimed at learning what impact the use of a fourth sub in extra time would have on the final result of a match. Normally teams are only allowed to use three subs, even if the game goes beyond the regulation 90 minutes.

The DFB said it had consulted with all of the teams affected before taking the decision.

"We are happy that all clubs see the sporting advantage of the rule and agreed to the change during this season's competition," said Peter Frymuth, the DFB's vice president responsible for football operations and development.

"Participating in the pilot project allows an assessment of the substitution in extra time in terms of its advantages, but it will also allows us determining possible negative impact on the competition."

By implementing the new rule, Frymuth said the DFB was also taking the well-being of the players into account. 

The new rule is to be used for the first time in Germany this Friday, when Arminia Bielefeld host Wolfsburg in the round of 16 in the women's cup competition. It is to be used in the men's game for the first time in their round of 16, which begins on February 7.

The new rule was first tried out at this year's Copa America.