The Football Association has released new guidelines that say players who suffer a concussion should not return to games for 19 days at the earliest.
The recommendations also say any player who is suspected of suffering a concussion should be immediately removed from action for the rest of the day.
As part of the guidelines, a player would not train or participate in any team activities for a full two weeks after the concussion.
If symptom-free at that point, the injured player may start walking or light exercise on the 15th day and add running drills on Day 16.
Non-contact training with the exception of heading and diving can resume on Day 17, and if cleared by a doctor, full training could resume on Day 18, before the player can take part in a game on Day 19.
For players under 19, each step after the initial two-week rest period is doubled, meaning the earliest they could play is 23 days after the injury.
"The paramount priority for The FA is player safety, and so the publication of these concussion guidelines is integral to achieving an unprecedented high level of care and safety for players at all levels," said Ian Beasley, the FA's head of medical services.