All 48 nations featuring at this summer's World Cup finals in the United States, Canada and Mexico have now named their official 26-man squads.
Several have already been forced to make alterations due to injuries, including Scotland, whilst others have seen players withdraw for personal reasons.
But how long are nations able to tinker with their squads? Find out below...
Well, FIFA have confirmed that changes can be made up to 24 hours prior to each of the countries opening group stage fixture, meaning England boss Thomas Tuchel, for example, would be able to replace an injured player in his squad up until 21:00 (BST) on Tuesday 16th June - a day before the Three Lions first World Cup assignment with Croatia.
However, it's worth noting that any replacements can only come from each of the teams provisional 55-player lists that were submitted to FIFA last month.
Should a player succumb to injury or need to return home after their team's first fixture, then no replacement is able to be called up.
In terms of goalkeepers, well the rules are far more relaxed, with FIFA allowing all 48 nations to replace a goalkeeper at any stage of the tournament should they be pick up an injury or fall ill.
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