Having a fourth substitution during extra time at the World Cup knockout stage would be welcomed by coaches, especially when teams have to play consecutive games over 120 minutes, Germany coach Joachim Loew said on Monday.
Loew said players were feeling the impact after a long season in Brazil's month-long World Cup with kick-off times in early afternoon adding more strain.
"This would be worth a consideration, to think if we had the chance as a coach to bring in a fourth player, especially after the round of 16 if you have several extra times to play," he told reporters.
Germany, who face hosts Brazil in the semi-finals on Tuesday in Belo Horizonte, needed 120 minutes to edge past Algeria in the last 16 but then advanced 1-0 versus France over 90 minutes. Three of their five matches had a 1300 local time start.
"Especially after a long (club) season, it is an interesting possibility and an interesting thought. One o'clock kick off is difficult, you feel the players' exhaustion afterwards. For a coach and the team it would be another option," he said.
Kick-off times in Brazil have been moved earlier to accommodate a global audience and especially European viewers.
Soccer's world governing body FIFA proposed the idea to the International Football Association Board (IFAB) two years ago but it failed to win the necessary 75% majority and was not passed into law.
Gerard Houllier, former France and Liverpool coach who is also the senior member of FIFA's technical study group (TSG) analysing trends and tactics at the World Cup, said days ago the idea should be resubmitted.